Study Unit

RiflesBy

Carl P. Wood

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01/22/03

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About the Author

Carl P. Wood grew up on a farm in West Virginia where hunting was

a way of life. Given his first .22 rifle at 9 years of age and his first

shotgun at age 10, Carl began a love affair with guns and shooting.

After serving in the U.S. Navy during World War II, he married and

set about earning a Journeyman machinist’s card in a shop of the

old tradition. He spent countless hours as a disciple in the shop of

the late gun writer and ballistics expert Phil Sharpe. Later, he

worked directly for Richard S. Boutelle, then President of Fairchild

Aircraft, on several development phases of the AR–15 rifle. Just a

few of Carl’s writing credits include a stint as shotshell editor of the

American Reloading Association Bulletin, current gun editor of West

Virginia Woodsman, field editor of Backwoodsman, and editor of The

Bird Dog Review. Carl wrote The Gun Digest Book of Sporting Dogs,

and the shotshell reloading section of Dean Grennell’s ABC’s of

Reloading. Working with metallurgist Jim Kelly, Carl wrote a series

of articles on black powder pressures and barrel steels, which were

published in Muzzle Blasts. These controversial articles resulted in

changes in the steels used to manufacture muzzleloaders.

iii

In this unit, we'll address the complete rifle,

emphasizing design, function, repair, and

modification of different type actions.

Following a brief history of rifle development,

the unit considers the rifle barrel, thoroughly

discussing barrel types, steels, and their

applications. The barrel section also covers barrel attach-

ments and their purposes. The purpose of the section on

trigger mechan-isms is to alert you to the dangers of work-

ing on triggers and sears, and to open your eyes to possible

legal complications. The final function/troubleshooting

sections address lever, pump, bolt, semiautomatic, double-

barrel, and single-shot action rifles.

When you complete this study unit, you’ll be able to • Explain the history and development of rifles

• Identify the different types of rifle barrels in relation to theirapplications

• Identify the different barrel steels

• Describe methods of barrel manufacture and methods forrifling during the manufacturing process

• Explain how to fit a barrel blank to an action

• Summarize the purposes for and installation of barrelattachments

• Recognize the liability associated with trigger work

• Identify the eight major functions of various rifle actions

• Troubleshoot the various rifle actions and identify tools usedfor rifle repair

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HISTORY OF THE RIFLE 1

Freshening Out and Reboring 4The Caplock 7The Advent of Metallic Cartridges 7

PRINCIPLES OF RIFLING 9

Bullet Yaw 9Proof Testing 12Nodes of Vibration 13Gas Cutting 14Bore Erosion 14

BARRELS 17

Outside Barrel Diameter 18Barrel Styles 18Ultralights 18The Accuracy/Weight Tradeoff 22Installing Barrel Liners 26Rifling 29Lapping Shotgun Bores 38

BARREL STEELS 41

Black Powder, or Gun Barrel Grade, Carbon Steel 41Ordnance Steel 43Nickel Steel 44Stainless Steel 44Installing a Barrel on an Action 46Turning Down Barrels 52Barrel Straightening 52Recoil Compensators 53Flash Suppressors 56

TRIGGER MECHANISMS 58

Trigger Adjustment 59Removing Two-stage Triggers 61Aftermarket Triggers 62Set Triggers 63

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FIREARM FUNCTIONS 65

Troubleshooting 66Some Essential Tools 70Lever-actions: Function and Troubleshooting 72The Sequence of the Eight Functions in

Popular Lever-action Rifles 75How Lever-actions Lock Up 78Drawbacks of Lever-actions 78Troubleshooting Lever-actions 78

PUMP-ACTIONS: FUNCTION AND TROUBLESHOOTING 88

The Sequence of the Eight Functions in Pump-action (Slide-action) Rifles 88

How Pump-actions Lock Up 90Troubleshooting Pump-actions 90Bolt-action Rifles: Function and Troubleshooting 93How the Eight Basic Functions Apply in

Modern Bolt-action Rifles 95Lock-up Systems, Bolt-action Rifles 97Multiple Locking Systems 98Gas Venting, Bolt-action Rifles 99Safeties on Bolt-action Rifles 100Manufacturing Bolt-action Rifles 100Troubleshooting Bolt-action Rifles 101Semiautomatic Rifles 106Sequence of the Eight Functions in

Autoloading Rifles 112Troubleshooting Semiautomatic Rifles 113

DOUBLE RIFLES 118

Troubleshooting Double-barrel Rifles 120Single-shot Actions 120The Sequence of the Eight Functions in

Single-shot Rifles 124Troubleshooting Single-shot Rifles 125

SELF-CHECK ANSWERS 129

EXAMINATION 131

1

HISTORY OF THE RIFLE

Scholars generally agree that guns were first used in China

and that gunpowder was invented in China. However, they

differ as to where it was first used to propel missiles. The

general consensus is that gunpowder was first used as a

missile propellant in hand cannons made of bamboo stems

bound together by leather. Apparently, stones were seated

over a charge of powder inside a bamboo tube. Some type of

slow match through a touchhole ignited the charge (Figure 1).

Note: In your first module, you received A History of Firearms,

which comprehensively details all types of early firearms.

This section limits its historical discussion to rifles. Also,

function/troubleshooting sections appearing later in this unit

detail historical developments of various rifle action types.

While the Italians are generally credited with developing guns

in the early period, the development of the rifled barrel is

almost certainly a German invention. We believe the first

rifling had straight grooves running parallel to the axis of the

bore. Apparently, early German experimenters thought that

causing a projectile to follow a straight line inside the barrel

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FIGURE 1—This illustration depicts what a bamboo hand cannon might have looked like. The drawing is entirelyconjecture, as we know of no existing bamboo-barreled guns. Only sparse written description remains.

would cause it to continue doing so after exiting the barrel.

Evidently, there is some truth in this straight rifling idea.

One of America’s premier barrel makers, the late G. R.

Douglas of Charleston, WV, experimented with straight

rifling. He verified that straight grooved barrels did shoot

better than the smoothbore, but not as well as the same

groove pattern in a suitable spiral twist.

We’ll probably never know who concluded that spiraled rifling

would improve the accuracy of a projectile by stabilizing it

like a gyroscope or a spinning top. Indeed, we can’t even be

sure that accuracy wasn’t an unexpected side effect of an

experiment. The stories surrounding the invention of spiraled

rifling are many. In 1984 Mr. Gottfried Berger of Suhl,

Germany, shared a noteworthy one with me at a black pow-

der rendezvous where we had several long talks regarding

German and American black powder guns.

Gottfried’s story concerns an apprentice gunsmith in Suhl

who became angry with his master and spitefully twisted a

barrel already cut with straight rifling grooves. Realizing the

enormity of his offense, the apprentice hurriedly filed the

flats straight to hide his misdeed. As the story goes, this bar-

rel became famous for its accuracy. The master gunsmith

couldn’t duplicate the barrel’s performance. Only upon close

examination did he discover the spiral effect twisting had

given the rifling.

The story goes on about how the gunsmith made many more

of these accurate barrels and became famous. Apparently, he

kept the twisted rifling a secret for many years.

At first, this story seems unlikely. However, given the difficulty

of seeing down a bore that can’t be unbreeched without

removing the breech plug, and considering the absence

of modern bore scopes and lights, it becomes somewhat

believable.

In any event, it’s almost certain that rifling didn’t afford

much advantage until the wheel-lock became popular.

Apparently, the mechanics and slowness of the matchlock

system prevented the shooter from holding the gun steady

long enough to benefit from improved accuracy.

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The Snaphaunce further improved the shooter’s ability to

deliver a projectile to the aiming point with the enhanced

accuracy of the rifled barrel. Then, around A.D. 1620, the

flintlock afforded more precision to the process of aiming

and discharging a firearm. Finally, we reached the point

where an accurate barrel enabled greater precision.

The rifled flintlock reached its zenith in the so-called

Kentucky Rifle, which was actually the Pennsylvania rifle

that provided the settlers with superiority over the native

Americans. This same Pennsylvania Rifle used in Kentucky

reached its zenith during the settlement of Kentucky and

Ohio (1770–1790) and became known as the Kentucky Rifle.

In addition to the great strides made by American gunsmiths

during this period, German gunsmiths were perfecting their

Jaeger (pronounced Yager) rifle (Figure 2).

FIGURE 2—The upper rifle is a Kentucky-style recreation by Master Riflesmith Dave Kidwiler of GerrardstownW.V. The Jaeger rifle at the bottom is a recreation by Master Riflesmith Mike Small of Hedgesville, W.V. Both ofthese rifles are fine examples of the working rifles of the frontier era.

The Jaeger rifle was a relatively short-barreled (24–28 inch)

gun in heavy caliber (.50–.90). As produced by the better

German gunsmiths, these guns were heavily carved, inlaid,

filigreed, and engraved examples of the best of the gun

maker’s art. The Jaeger also had a relatively short, yet

heavy, stock as compared to the long, slender, graceful,

Kentucky rifles.

The Kentucky rifle barrel lengths ranged from a short 36

inches to 50 inches or longer. The stocks were also very

slender, almost to the point of fragility. Kentucky rifles were

of widely varying calibers with the majority in the .40 to

.50 caliber range in the mid to late 1700s. In the Eastern set-

tlements, following the disappearance of elk and bison and

the end of Indian fighting in the early 1800s, smaller calibers

were usually made. The .36 caliber is representative of newly

made guns used in settlements east of the Mississippi in the

latter half of the nineteenth century (Figure 3).

The high price of lead and powder also contributed to smaller

calibers. So, too, did the knowledge that shot-out bores could

be enlarged by “freshening” and “reboring,” therefore extend-

ing the firearm’s use.

Freshening Out and Reboring

Early rifles didn’t profit from the high-quality barrel steels

available today. Instead, they were formed from relatively soft

wrought iron. With each firing, the wrought iron suffered

moderate wear when the hot gases reacted with the surface

steel. Also, chemical reactions caused by burning sulfur in

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FIGURE 3—This .36 caliber halfstock is a recreation, by Carl Wood, of a late 1800s squirrel rifle made by D. Markerof Charles Town, WV. It’s as near to an exact copy as is humanly possible. To make the authentic copy, it was necessary to make the lock and furniture by hand.

Rifles 5

the powder helped erode the barrel. When sulfur dioxide

(SO2) absorbed water from the moisture (H2O) in the air, it

became sulfuric acid (H2SO4). The acid corroded the bore.

Eventually, bore wear affected barrel accuracy. When a rifle

became too inaccurate, the owner took it to a gunsmith for

“freshening out.” The gunsmith accomplished freshening out

by lightly reaming and lapping the top of the lands enough to

clean them up into a smooth surface like the original bore.

The lands are the tops of the raised rifling between the

grooves.

Figure 4 shows the form of rifling used in the M1917 Enfield.

Notice the five lands and the five grooves, which are of equal

width. The bore is .300 inch. The grooves are .005 inch deep.

Figure 5 shows the rifling of the Metford-type rifle, also used

in the Model 99 1939 7.7 mm Japanese rifle.

FIGURE 4—Lands and Groovesof the M1917 Enfield

FIGURE 5—Lands and Groovesof the Metford

The usual reaming removed .010 inch from the top of the

lands and resulted in a bore size .020 inch larger than the

original diameter (.010 inch off each side).

Note: The figures are approximate, as most gunsmiths of the

era lacked precision measuring equipment to measure incre-

ments of .001 inch. They just reamed and polished the barrel

until it regained a smooth, regular surface.

Sometimes the bore was in such poor condition that it

required more than .010 inch to clean up the lands. In such

cases, the gunsmith would rebore the barrel to restore the

smooth track along which the ball passed and thus restore

accuracy.

Reaming the tops of the lands increased the rifle’s caliber. In

such cases, the gunsmith made a new bullet mold to fit the

larger land diameter of the barrel (Figure 6).

Freshening out resulted in many different calibers, as each

freshening usually resulted in a two-caliber increase. A cal-

iber is .01 inch, so a .40 caliber muzzle-loading rifle has a

land diameter of .400 inch. A rifle that was originally a

.40 caliber and had been freshened twice would likely be

about .44 caliber. (We measure modern rifle barrel bores

differently.)

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FIGURE 6—Drawing of the Pilot Reamer used to “freshen” muzzle-loading barrels starting in the mid-eighteenth century. Gunsmiths made earlier reamers by inserting a steel cutter in a wooden rod. Thewooden type wasn’t very accurate and required a lot of hand lapping to attain an even surface.

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Usually, rifle barrel grooves could be freshened out twice

before requiring reboring. During the reboring process, the

gunsmith dug all rifling out of the barrel. Then, the gunsmith

would cut new rifling, just as when making a new barrel.

Next, the gunsmith repeated the freshening out and reboring

processes until the bore required too large a ball-and-powder

charge for the rifle owner’s purposes, or until the walls of the

barrel became too thin to recut the rifling. At this point, the

gunsmith would usually bore out the rifling and make the

gun into a smoothbore. The shooter could then use the

smoothbore as both a rifle and shotgun, depending upon

whether it was loaded with shot or ball. Sometimes such guns

were loaded with both shot and ball. Such loadings, known

as “Buck & Ball” loads, were the standard loadings of such

early American Colonial troops such as Roger’s Rangers.

The Caplock

The advent of the Caplock further enhanced rifle accuracy by

enabling much faster and dependable ignition. The Caplock

used a copper cup filled with fulminate of mercury. The cup

was set over a small nipple leading into the powder charge.

When the strike of the hammer exploded this cup, it immedi-

ately ignited the black powder charge, thus firing the rifle.

Importantly, the caplock was far more dependable than the

flintlock in unfavorable weather conditions (rain and snow).

The Advent of Metallic Cartridges

The next development of significance to rifled barrels was

cartridges. While the Ferguson and Hall rifles worked fairly

well, it wasn’t until the appearance of the metallic cartridge

that really significant advances in rifles occurred. The metal-

lic cartridge offers an efficient method of sealing the breech

on an open-breech rifle. During firing, the pressure of the

exploding powder gases expands the case against the walls

of the chamber.

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Self-Check 1

At the end of each section of Rifles, you’ll be asked to pause and check your understanding of what you have just read by completing a “Self-Check” exercise. Answering these questionswill help you review what you’ve studied so far. Please complete Self-Check 1 now.

Indicate whether the following statements are True or False.

_____ 1. The Jaeger rifle was a slender, graceful gun.

_____ 2. Matchlock was the first ignition system that allowed careful shot placement.

_____ 3. Reboring is the removal of the worn rifling and cutting new grooves in a worn barrel.

_____ 4. A caliber is .02 inch.

_____ 5. Kentucky Rifles had barrel lengths as long as 36″ to 50″.

Check your answers with those on page 129.

Rifles 9

PRINCIPLES OF RIFLING

Bullet Yaw

In this section, we’ll introduce some highly important factors

that determine a rifle’s accuracy. The student studying rifling

and the principles that govern rifle performance should

understand bullet yaw and nodes of vibration.

Bullet yaw is an offspring of the Coriolis effect, which causes

water to form a whirlpool as it goes down a drain and a toy

top to travel in a circle as it spins. Bullet yaw causes a bullet

to travel around the axis of its flight in a spiral pattern. If

you envision a straight line, which we’ll call the “true bullet

path,” the effect of yaw is to make the bullet travel in a spiral

course around this true path. This effect is entirely different

from, but a side effect of, the bullet spin imparted by the

rifling (Figure 7).

The bullet yaws at a much slower rate than it spins. For

example, suppose you fire a bullet from a barrel having a

rifling twist rate of 1 inch in 12 inches, which is a fairly com-

mon twist rate in modern rifles. The bullet spins at the rate

of one turn for every foot of forward travel. This may seem

like a fairly slow rotation until you consider that a bullet

from a 1-in-12 pitch barrel traveling at 3,200 feet per second

(fps) travels 100 yards in .097 seconds. It spins 300 turns in

.097 seconds, which we’ll round off to .1 second to simplify

matters. Therefore, by multiplying 300 turns in .1 second by

10 to approximate how many times it spins in one full second,

you come up with about 3,000 revolutions per second (rps).

FIGURE 7—As a bullet yaws, it spirals around the axis of its true line of flight.

Rifles

Furthermore, multiply 3,000 rps by 60 seconds to approxi-

mate how many times it spins in one minute. The result is a

rotational rate of 180,000 revolutions per minute (rpm),

indeed a high rotational rate. It’s common for improperly

constructed bullets to vaporize in flight by such ultrahigh

rotational rates. I demonstrate this effect at gunsmithing

seminars in the following way. I use a Remington model 721

magnum action, probably the strongest action ever sold as

an “over the counter” item. The gun was chambered for the

.300 Weatherby cartridge. I loaded it with the 100 grain

Speer “Plinker” bullet. It shot well over SAAMI (Sporting Arms

and Ammunition Manufacturers Institute) specifications—

a charge of H414 powder for a bullet velocity, measured with

a chronograph, as 4,400 fps.

When fired at a 40 inch, square-shotgun pattern sheet at

30 yards, the 100 grain Speer, traveling at 4,400 fps, causes

a ragged-edge, 8 to 10 inch hole in the center of the paper.

Also, a spattering of tiny pinholes surrounds the paper.

Occasionally, there will be a crescent-shaped hole in the

paper where the thoroughly flattened bullet jacket went

through the paper. This is no fault of the bullet, as it was

designed to be fired at velocities of 2,000 fps or less. It sim-

ply isn’t capable of withstanding the terrific centrifugal forces

generated by the rotational velocity of such a loading, which

travels 100 yards in .076 seconds. Using the same method as

before, and allowing for the faster barrel twist of the .300

Weatherby, we arrive at a rotation of 225,000 rpm (Figure 8).

Warning: Overloading ammunition can prove fatal! Never exceed

manufacturer specifications when hand-loading ammunition.

Throughout this document, I provide facts about overload,

which pertain to clearly unsafe practices and to illustrate the

effect of excessive spin on a particular bullet. I have worked

with chronographs, pressure barrels, proof guns, and similar

experimental equipment for many years as part of a business

that researches and develops new loadings for both metallic

and shotshell ammunition. Obviously, someone must make

the first loading of experimental ammunition. Only someone

with many years of experience should make such experimen-

tal loadings, and under carefully controlled conditions. When

I make a loading, such as the high-velocity .300 Weatherby

round, I use my experience and judgment to predict the

10

Rifles 11

outcome. I base my hypothesis on much education and

research. Even then, the first firings of such loadings will be

in a pressure barrel in an enclosed firing chamber under

stringent safety procedures.

Warning: Education Direct has no control over experiments

that a student may conduct. Because it’s unlikely a student

can match Mr. Wood’s experience, we advise in the strongest

terms that you don’t assemble any hand load, including so-

called “Blue Pills” or “Proof Loads,” which exceed industry

standards. We disclaim any responsibility if you disregard

this warning.

When you must test the safety of a loading, there’s a safe, yet

less desirable, method of testing. Tie a rifle in an old automo-

bile tire for test-firing purposes. With this method, the stock

is inside the rim of the tire and the forend tied down onto the

tire. You fire the gun by pulling the trigger with a string from

a safe distance (Figure 9).

FIGURE 8—A 110 grain bulletleft this 2 1/2 inch hole in apiece of cardboard when overloaded with the samecharge just described. In thisinstance, the target was penetrated just 15 yards fromthe muzzle. Notice the tinypinholes, which indicate thatthe bullet is breaking up.

Proof Testing

Where no proper facilities are available for test-firing, the

practice, known as proof testing, is to fire a load with a 20

percent increase in the powder charge usually used in the

rifle. Then, carefully examine both the rifle and fired cartridge

for signs of excess pressure. Assuming that upon careful

inspection the gun and fired case show no signs of trouble,

some people believe the gun may be fired using a charge 20

percent less than the proof load. WE DO NOT RECOMMEND

THIS PRACTICE. After you determine the resultant pres-

sures, you decide whether the loading is safe for use in a

particular gun. In the instance just discussed, we decided

that the load would be safe to fire in only the strongest

actions such as the Remington 721 and Fahrquahr actions.

Warning: Most progressive-burning smokeless powder ignites

at a rate proportional to the pressure within the bore. If the

pressure is too low, the powder may not burn before the bul-

let exits the barrel. If it’s too high, the powder may detonate

(explode rather than burn). Ammunition companies specially

load proof loads used in factories using powder and powder

charges carefully developed with safety in mind to create a

specific pressure level in the bore. Simply increasing the

charge 20 percent, as previously mentioned, is meaningless

unless the necessary equipment is available to determine

exactly what pressures are being generated. Also, even if a

rifle reveals no apparent damage after firing a proof load(s),

it still may not be safe. Even though it hasn’t blown up, the

stressed material in it may yield some. The result can be

anything from excessive headspace because the action

Rifles12

FIGURE 9—This photo depictsa muzzle-loading rifle mountedin a tire for test-firing purposes.The tire cushions the recoil.Note that you should neverfire a rifle from solid mounts,as the recoil will likely breakthe stock.

Rifles 13

stretched, to an undetected crack in the locking lug or some

other part. Proof testing is dangerous work. You should refer

all proof testing to an independent laboratory set up specifi-

cally for this purpose.

Nodes of Vibration

Another factor in rifle performance, or accuracy, is barrel

vibration. When a gun fires, the effect of the sharp explosion

is similar to what happens if you strike a hard blow to a

metal barrel with a hammer—it vibrates. The vibrations

cause the barrel to bend slightly as the shock waves from the

explosion travel along its length. (The effect is similar to the

waves caused by throwing an object into a pond.)

The waves of vibration travel up the gun barrel and cause its

muzzle to wave back and forth. The waves, known as nodes

of vibration, are the bane of accuracy. Understandably, the

muzzle waving back and forth from the effect of the vibration

affects accuracy by the point in the barrel’s swing at which

the bullet exits. Sometimes a hand loader can develop a load

that causes the bullet to exit the muzzle at the center of the

node of vibration. This greatly improves accuracy, as the

muzzle is at a pivot point (Figure 10).

FIGURE 10—This drawing depicts nodes of vibration. The most accurate load is the one that exits thebarrel at the node instead of at the overtone of swing.

Extreme internal pressures generated when you fire a mod-

ern rifle cause the bore surface to become superheated,

which can also affect accuracy. The first few layers of mole-

cules of the surface steel actually melt. Eventually, depend-

ing on how heavily the shooter uses the rifle, the slow

removal of surface metal inside the bore significantly con-

tributes to barrel wear. The major causes of barrel wear are

gas cutting and erosion ahead of the chamber caused by the

high-speed passage of partly burned particles of powder.

Note: Internal bore conditions are very important to accuracy

in a rifle. Allowing a barrel to rust from lack of cleaning ruins

a good barrel. We’ll discuss more about cleaning later.

Gas Cutting

Powder gases leaking past the bullet cause gas cutting. The

powder gases subject the inner barrel surface, where they

pass between the bullet and bore, to high-pressure friction

and cutting. You can best counter gas cutting by using prop-

erly sized, well-made bullets.

Bore Erosion

Bore erosion, just ahead of the chamber, is caused by the

friction of burning powder particles. The particles subject the

area to extreme abrasive action during the few nanoseconds

that the bore surface melts, or at least softens. The extreme

heat generated by burning powder under high pressure melts

the bore surface.

You can greatly lessen bore erosion by using lighter-than-

maximum loads. Some calibers, which use large amounts of

powder in a relatively small bore, erode their barrels much

faster than less-powerful calibers. Cartridges, such as the

.220 Swift, .300 Weatherby, .280 Remington, and other

“overbore” calibers, are especially bad at eroding bores.

No reason exists to use maximum loads in most overbore cal-

ibers for hunting or target shooting. When loaded down to

acceptable pressures, such calibers won’t erode barrels any

faster than lower-powered calibers.

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Note: Many believe that single-base powders cause more

erosion than double-base powders.

You can best detect bore erosion by looking through the

clean barrel from the breech end, when possible, and closely

examining the area just ahead of the chamber for smoky,

dark-appearing sections. Severe bore erosion is evident when

the rifling ahead of the chamber seems to be worn away for

some distance. If, when you look through the breech end, the

barrel exhibits wear to about six inches ahead of the chamber,

heavy erosion has taken place, which severely diminishes

accuracy.

In such an instance, if high accuracy is required, the only

recourse is to replace the barrel, or to install a barrel liner.

Personally, barrel liners I’ve used have never provided top-

notch accuracy. I consider five shot groups of less than an

inch at 100 yards to be top accuracy. Still, some folks tell me

they get excellent accuracy from barrel liners.

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Self-Check 2

Fill in the blanks in the following statements.

1. Gunsmith’s should _______ make experimental loadings for which they have no test data.

2. You replace a rifle barrel when the effects of erosion won’t meet the _______ needs ofthe owner.

3. The major causes of barrel erosion are _______ by powder particles and gas cutting.

4. The seemingly insignificant change of a few grains of powder sometimes results in greatly_______ of the barrel vibration.

5. Powder gases leaking past the bullet cause _______.

Check your answers with those on page 129.

Rifles 17

BARRELS

While barrel manufacturing is beyond the scope of this

study unit, you should know enough about barrels to identify

them and make recommendations to customers based on

prospective use.

Since barrels are manufactured for different purposes, many

styles are available. The ordinary modern rifle barrel is some-

where between .17 and .45 caliber. Lengths will vary from

18 inches for a carbine-style rifle to 26 inches for a heavy

caliber designed for maximum velocity from overbore car-

tridges and loads. Twenty-six inches is the maximum practi-

cal barrel length. Rarely will a modern rifle barrel be over

26 inches long. Modern smokeless powder burns a normal

charge within about 22 inches of bore length, and most car-

tridges develop their major velocity potential within 24 inches

(Figure 11).

As modern shooters appear willing to sacrifice a little velocity

for a lighter, easier-handling rifle, the latest trend seems to

lean toward the shorter 22 inch barrels. Still, probably more

24 inch barrels are being manufactured for centerfire rifles

today than all other barrel lengths combined. It’s possible,

for example, to develop more velocity in a .30/06 shooting a

150 grain load in a 26 inch barrel. However, the increased

velocity afforded by the extra 2 inches is only about 110 fps

(depending on the burning rate of the powder being used).

Such an increase is not sufficient to warrant the additional

weight and cumbersome handling of the longer barrel.

Conversely, in overbore cartridges such as the .300

Weatherby, the additional velocity afforded by a 26 inch

barrel is about 250 fps (again depending on the burn rate

of the powder). A velocity of 250 fps is often considered

enough gain to justify the additional length.

FIGURE 11—Illustration of a Barrel

Outside Barrel Diameter

To some extent, we determine the outside barrel diameter by

bore diameter, as safety requires sufficient wall thickness.

Another important consideration is prospective use. Generally,

the action the barrel must fit determines its rear diameter.

Still, in many instances, we determine barrel diameter by

whatever bar stock of barrel steel is available at the best

price.

Barrel Styles

Often, the finished barrel diameter bears little relationship

to the original bar stock. All types of tapers and turnings can

be made to suit customers’ or barrel makers’ designs. Barrels

range from slim ultralight styles thinned down as far as safe-

ty considerations will allow, to heavy 30 to 40 pound “bull”

barrels that have larger diameters than the receiver rings

they install on. Myriad contours and dimensions fall between

such extremes.

Ultralights

Hunters carry the ultralight-style barrel in extreme condi-

tions such as the steep terrain encountered while mountain

hunting for sheep and goats. In such environs, every ounce

saved in rifle weight is like a pound by day’s end. Great care

must be taken in trimming off barrel weight through reduced

diameter. Back in the days before the Sporting Arms &

Ammunition Manufacturer’s Institute (SAAMI) introduced

specs, instances occurred where barrels were “turned” a little

too thin to reduce weight. The results were bulged and even

blown chambers!

Note: The purpose of the Sporting Arms & Ammunition

Manufacturer’s Institute (SAAMI) is to furnish standards to

which all American manufactured arms and ammunition

could comply. SAAMI specifications replaced the formerly

chaotic manufacturing tolerances of the arms industry,

which varied according to each maker’s preference. SAAMI

has been a boon to all who work with firearms.

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Rifles 19

Often, ultralight barrels suffer from relatively poor accuracy

due to “barrel whip.” Barrel whip, caused by insufficient

barrel stiffness, greatly exaggerates the effects of nodes of

vibration.

Featherweights

Next up the scale of barrel stiffness from ultralights is the

featherweight barrel. This type is somewhat heavier in the

chamber area and the contour just ahead of the chamber. By

allowing more metal to remain in this critical area, the barrel

maker provides two major advantages. First, and of prime

importance, is the additional strength in the chamber area,

which becomes critical in case of overload.

Note: Other factors contributing to increased chamber

pressures include

• Improperly seated bullets

• Cases “stretched” by reloading and resizing that haven’t

been correctly trimmed

• Improper crimping

• Unusually thick brass that has less powder capacity

• Hot “magnum” primers used with an easily ignited

powder

• Rusted or obstructed bores

• Firing under unusually high temperatures

The second advantage of allowing more metal to remain is

the additional stiffness this relatively small increase in barrel

weight affords. A slender barrel will vibrate more and faster

than a larger diameter barrel, given the same impetus. A

slight weight increase in the chamber area often provides the

potential for higher accuracy.

Light Hunting Barrels

The next heavier barrel type is often called a “Light Hunting”

weight barrel, although various manufacturers have their

own pet names for such barrels. There’s considerable dispar-

ity of design in this barrel category. Some makers believe

that a fast taper is the best answer to the vibration problem.

A barrel made following this school of thought tapers rapidly

from just ahead of the chamber area to a point about one

third the distance to the muzzle. It then changes to a very

slow taper for the last two thirds of the muzzle end.

Another school of thought professes that a straight taper

from the area just ahead of the chamber to the muzzle

affords more stiffness and accuracy. This belief leads to a

somewhat heavier barrel on a light hunting rifle, but does

seem to produce very accurate barrels in the lighter weights.

Standard Weight Barrels

Most factory sporters (standard hunting rifles) use the stan-

dard weight barrel.

Light Varmint Barrels

Next up in weight is the light varmint weight barrel. It’s

heavier than the light hunting barrel but lighter than

barrels such as those on the Remington Model 700

Varmint Specials (Figure 12).

Varmint Special Barrels

The varmint special is one of the most successful over-the-

counter designs available today. It produces remarkable

accuracy. Mine consistently produces 200 yard groups of less

than an inch diameter with carefully developed hand loads

and match-grade bullets.

Rifles20

FIGURE 12—This Remington “Varmint Special,” mounted with a 4 �� 12 Redfield Ultimate Illuminator sitting atopa shooting rest, is the ultimate varmint shooting setup. This rifle is capable of one inch groups at 200 yards.

Rifles 21

Heavy Varmint Barrels

Next in weight and stiffness are the heavy varmint barrels,

often weighing in excess of 14 pounds. To my way of think-

ing, they don’t produce enough improvement in accuracy to

justify their uncomfortable and awkward weight. However,

with careful and extensive experimentation and many differ-

ent powder loadings, charge weights, and bullet and case

combinations, you can obtain an accuracy level greater than

most of us can shoot under field conditions.

Bench Rest Barrels

Bench rest guns use the heaviest barrels. It really is necessary

to fire guns with “bull barrels” off benches, as many bench

rest rifles weigh as much as 40 pounds. No one can shoot

them effectively in handheld positions. From the bench, these

massive bench rest barrels are most accurate at extended

ranges. They are stiffer, and the sheer static energy resulting

from their weight largely nullifies the effect of barrel vibrations.

Discussion of bench rest barrels brings an interesting story

to mind. In an effort to fire even tighter groups, bench rest

shooters are forever experimenting with bedding methods

and barrel mounting. Back in the early 1950s when Dubois,

PA hosted the bench rest championships, some shooters

successfully bedded barrels in Silly Putty, which is literally a

slow liquid. Yes, I’m referring to the same substance sold as

a children’s toy—the stuff that slowly creeps into the tiniest

of crevices. Silly Putty has some interesting properties. If you

leave a ball of it on a table for several hours, it will end up as

flat as a pond’s surface. At normal temperatures, it won’t

move or flow rapidly under any circumstances. When frozen,

if you strike it with a hammer, it shatters like glass. Form it

into the shape of a stick, and if you try to bend it rapidly it

breaks. Bend it slowly, though, and it will assume any

shape. Lay pieces of it together for a few hours and it will

flow into one solid mass again.

The properties of Silly Putty help illustrate just how impor-

tant a rifle’s bedding is to performance. Naturally, using Silly

Putty as a bedding material is impractical because unless the

rifle stays in a flat and level position, the putty will flow out in

Rifles

a few hours. In the spirit of enhanced accuracy, we chiseled

out an oversize channel for the barrel in a stock. This allowed

no wood-to-metal contact except at the bottom of the action

where it mounts with screws to the stock. Then, we slowly

filled the space between the stock and barrel with Silly Putty.

When we fired the gun, the putty acted as a solid bedding for

the barrel with absolutely no stress or uneven pressure on

the barrel at any point. This resulted in some really good

groups and proved that a barrel must be perfectly bedded

to achieve its maximum accuracy potential.

Still on the subject of bedding, the practice of “floating” a

barrel seems to be the most popular bedding method used

today. A rifle has a properly floated barrel if you can pass a

dollar bill freely between the stock and the barrel all the way

down the forend until it reaches the receiver ring, which

should be resting solidly on the stock. Floating avoids

changes in the impact point due to stock movement from

both temperature and humidity changes.

The new fiberglass or graphite stocks, with the barrel firmly

bedded in epoxy, are claimed to eliminate all movement of

point-of-impact due to temperature and humidity changes.

It seems as if they do, to a large extent, eliminate “zero”

changes. They also greatly reduce weight and are seemingly

stronger than wood. Many shooters prefer them, and I have

no quarrel with those who do. Their disadvantage is that

they’re cold to the touch in winter, and for me, a camouflage

plastic stock will never equal the beauty of a piece of fine

wood.

The Accuracy/Weight Tradeoff

Getting back to barrels, there’s a definite tradeoff between

accuracy and lighter barrel weight. The point at which light-

weight barrels start to severely handicap accuracy varies

inversely with the caliber and power of the loadings. A barrel

chambered for a .22 long rifle will likely be more accurate

than the same barrel profile and weight chambered for a

.22 WRF Magnum, and certainly more accurate than if

chambered for a .22–250 Remington. I have a Winchester

Model 52 Sporter, made in the 1940s, which will shoot .260

inch diameter five-shot groups at 50 yards using Eley “Black”

22

Rifles 23

target ammunition. I recently acquired a Ruger M77/22

Magnum chambered for the .22 Winchester Magnum Rimfire

that consistently shoots .500 diameter 100 yard five-shot

groups with RWS FMJ match ammunition. This little rifle

has shot 100 yard groups as small as .170 inch over bullet

diameter. So, it’s possible to achieve high accuracy from

lightweight barrels in low-powered loadings. When we try to

use heavy loads in light barrels, though, the vibration upon

firing destroys accuracy (Figure 13).

A barrel’s diameter and stiffness are important in obtaining

accuracy, as is its weight. I demonstrated this back in the

1950s while working for Fairchild’s Armalite division on the

development of the AR-15.This rifle later became the Army’s

M-16 standard-issue rifle. One of the problems we addressed

was excessive rifle weight. Every ounce of rifle weight is an

ounce of ammunition weight a soldier can’t carry due to lim-

its on just how much weight the average man or woman can

carry. Naturally, the objective was to design the lightest pos-

sible rifle that would meet service weapon requirements.

One of the ideas we tried concerned reducing weight by using

a Dural (aircraft grade Duraluminum) barrel with a stainless

steel liner. Although I can’t recall the exact figures many

years later, the Dural barrel weighed much less than the

FIGURE 13—This Ruger M77/.22 Caliber Winchester RF Magnum is a highly accurate 150 yard varmint andsquirrel rifle. It’s one of the most accurate rifles I have ever shot.

steel barrel. Deflection tests proved it to be nearly as stiff as

the steel barrels we had been using, and we expected great

things from this promising design. A lack of accuracy soon

dampened our enthusiasm. The rifle was chambered for the

.222 Special cartridge furnished by Remington, which later,

with slight modifications, became the .223 military round

used in the AR-15 and M-16 military rifles (Figure 14). We

had averaged two inch groups at 100 yards with a steel

barrel. However, the Dural/steel barrel opened up 100 yard

groups to around six inches or more, which the military

service didn’t accept as an accurate weapon.

Armalite also tried making an even larger diameter barrel,

which was stiffer than the steel barrel but still weighed only

about half as much. Although this improved accuracy some-

what, it still wasn’t acceptable. I was convinced that the

accuracy problem was the lack of weight. I determined this to

be true by turning down one of the inaccurate Dural barrels

on a lathe and making a lead sleeve that I installed on the

barrel to duplicate the weight of the steel barrel. This lead-

sleeved barrel wasn’t nearly as stiff as the steel barrel, but it

shot nearly as well, giving groups on the order of 2 inches at

100 yards.

Giving up on the Dural military barrel, Armalite, under the

“S-F Industries” (Sherman Fairchild) name, tried to sell a

Dural-barreled rifle built on a Remington bolt-action. It was

chambered for the .30 NATO (.308 WIN.) to meet the need for

Rifles24

FIGURE 14—This is a box ofthe first lot of .22 caliberammunition made for themilitary. With slight modifica-

tion, this round became the.223 NATO round. This is oneof only a very few survivingboxes of this round—a collec-tor’s dream.

Rifles 25

an extremely light rifle, known as the Para-sniper, for moun-

tain hunters. Once again, the accuracy was just too poor.

I had a Para-sniper for about six months trying to get it to

shoot accurately. Even with very light loads that pushed a

120 grain bullet at only .30-30 velocity (2,300 fps), 100 yard

five shot groups were at best four to five inches. When the

velocity was brought up to standard .308 velocity (2,800 fps

with a 150 grain bullet), five shot groups opened up to

around 8 inches at 100 yards (Figure 15).

The experiences we just discussed convinced me beyond

doubt that weight, serving in the role of static energy, plays

a large part in the accuracy of a rifle barrel. This leads me

to conclude that we can only obtain optimum accuracy from

a barrel that’s both stiff and fairly heavy.

FIGURE 15—Shown is an advertisement for the S-F aluminum barreled rifle. Only a few such rifles were made.

Rifles

Installing Barrel Liners

Only those who have acquired sufficient hands-on experience

with the proper metalworking tools should attempt to install

barrel liners. Most barrel liners come with complete and spe-

cific installation instructions. Still, the following procedures

contain hints that can prove helpful if you decide to perform

the task. The first procedure—a head and shrink process—is

the same that we used to install the stainless steel liner in

the Dural barrel during the AR-1 project.

To install a .30 caliber stainless steel liner inside a barrel,

first grind the stainless liner on a Landis Centerless Grinder

to an outside diameter of .362 inch. Next, carefully bore

the barrel to an inside diameter of .360 inch. Tolerances are

+/–.0004 inch on the liner outside diameter and +/–.0008

inch in the barrel (inside diameter). This provides an interfer-

ence fit of .3624–.3592 inch on maximum and .3616–.3608

inch on minimum, so you have .0032 inch maximum to

.0008 inch minimum interference fit. Such tolerances are

as close as you can reasonably hope for and a lot closer

than those used in most gunsmithing shops.

Heat the bored barrel in a furnace, oven, or other heat

source to about 300° F.

Caution: Do not heat above 300° F, as overheating might

weaken heat-treated barrels.

Place the liner in a freezer set to the lowest possible tempera-

ture. Usually, 0° F will suffice.

Place the heated barrel in a secure position, and wipe a tiny

bit of high-temperature oil on the end of the cold liner before

rapidly driving it in.

Caution: Drive the liner in before it has time to warm and

expand. Do the job right the first time, as once the barrel

cools and the liner expands, they’re fixed in place for all time.

Many gunsmiths get into trouble installing liners as just

described because their machinery isn’t accurate enough for

this type of installation. A barrel liner installed in this man-

ner becomes an integral part of the barrel. The only way to

remove it is to bore it out, which is as it should be. It’s the

only method that you can depend on to produce acceptable

accuracy.

26

Rifles 27

Note: The only way to improve upon this type of liner instal-

lation is to pull a carbide burnishing button ground, fur-

nished by the liner maker, through the barrel to burnish the

surface for longer wear. This also brings the bore diameter

back up to bore nominal size after liner installation. Where

the interference fit was on maximum (liner at the top of the

tolerance and barrel bore at the minimum size), the bore

diameter could reduce enough to cause slight pressure

increases in a heavy-walled barrel.

Tinning

Another method of installing barrel liners is by boring the

barrel out to a diameter that produces a bore about .002

over the diameter of the liner. The liner is “tinned” (coated

with solder) and the rebored barrel inside diameter thorough-

ly cleaned and also tinned as well as possible. It’s not easy to

get a good tinning job throughout the length of the barrel

inside a small diameter hole. Do as good a job as possible

and use plenty of soldering flux. If the liner is completely

tinned, it will carry enough solder with it to fill the voids.

Caution: The diameters of the bore and liner must be within

a couple thousandths of an inch. If more clearance exists,

the solder won’t fill all the voids between the barrel and liner.

When you fire the gun, the thin walls of the liner may

expand to fill any voids. This will result in an uneven bore

diameter and adversely affect accuracy.

Prior to tinning the liner, place a small amount of high-

temperature grease or welding Spatter Guard inside each

end of the liner’s rifled bore to prevent solder from creeping

inside the bore. It’s almost impossible to remove solder from

the inside of a bore without causing damage.

Note: In the event solder somehow manages to get inside the

liner, the best removal method is to melt it out and wipe the

bore with an oily rag while it’s still hot.

After having tinned both the liner and the rebored barrel,

heat them both above the melting point of the solder. Then,

hold the barrel securely while you tap the tinned liner into

the hole in the barrel. I use an old vise and heat the jaws of

the vise to a dull red with a torch so a section of the barrel

doesn’t cool before I seat the liner.

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Note: It’s almost impossible to perform this type of liner

installation without having an assistant nearby. While you

work on one part—either the barrel or liner—the assistant

keeps the other one hot. One person just doesn’t have

enough hands.

Warning: This type of liner installation is very dangerous. The

barrel and liner are hot, and solder spatters off the liner as

you tap it into place. Furthermore, you’re working with a

hot vise. Always use heavy gloves and good safety glasses

(the type that covers the sides of your eyes) with safety

lenses thick enough to be safe if hit by hot solder. Above

all, use good sense and be careful.

The Epoxy Method

A third method of installing barrel liners begins by boring the

barrel in the manner described for soldering. Then, instead

of soldering the liner into place, use a slow-setting epoxy glue

to hold the liner in place. I haven’t personally obtained good

results from this method, but I have heard good reports from

several gun shops that epoxy liners in.

The epoxy glue’s lack of hardness troubles me. It seems as if

the pressure of firing would crush the glue to powder unless

I used a heavy-walled barrel liner. To verify my suspicions,

I ran a hardness test. A good modern steel barrel has a

Rockwell “C” scale hardness on the order of 30 Rockwell. A

wrought iron muzzleloader barrel has a hardness of about

20 on the same scale. When I ran a Rockwell test on some

epoxy advertised as suitable for installing barrel liners, I had

to go to another Rockwell scale to get a reading at all. There

were indications that the glue was around 2 on the C scale,

but it crushed and the reading was not reliable. Obviously,

the test did little to relieve my suspicions concerning the

epoxy method.

Final Thoughts on Barrel Liners

You shouldn’t use barrel liners in barrels chambered for

“Bottleneck” cartridges. You can use barrel liners for .22

Rimfires, straight-sided black powder cartridges, and muzzle-

loading rifles. A competent barrel liner installer can add

considerably to his or her business installing barrel liners in

28

Rifles 29

shot-out muzzle-loading rifle barrels. With the increasing

popularity of muzzleloader deer seasons and the general

muzzle-loading craze, a lot of folks are dragging Grandpap’s

old “smoke pole” out of the attic and relining or recutting it

for safe use.

As noted earlier, I never personally had barrel liners deliver

accuracy of less than one inch groups at 100 yards. The

ones that delivered the best accuracy were installed by the

heat-and-shrink process.

Rifling

Hand Rifling

Until well after the Civil War era, gun makers made rifled

barrels by hand cutting the rifling. In this process, a rifling

rod pulls a rifling cutter through the barrel. A rifling guide

turned in spiral grooves by a “rifling master” (or pattern)

guides the rifling rod in a spiral rotation. As the cutter is

pulled along, it rotates in the pattern set by the rifling master.

Note: The rifling master’s index plate has a hole for each bar-

rel groove; that is, a rifling master index plate for a six-groove

barrel has six index holes.

The “hook cutter” is usually pulled through the barrel a pre-

determined number of full passes through each rifling groove.

Four passes in each index position is a good average. For

example, after the cutter is pulled four full passes through

the barrel with the rifling master set to the first index hole, it

is run out the breech end to clear the rifling. Then, the index

pin is moved one hole clockwise in the rifling master, and oil

is squirted into the next groove before seating the cutter in it.

The cutter is once again pulled through the barrel four times.

After the cutter is pulled through the same number of

strokes in each index hole, it’s run out the breech end of the

barrel. Then the adjustment wedge or screw is moved to seat

the cutter about .002 inch deeper.

Note: If the rifling machine uses a steel cutter rod having a

screw-adjustable cutter with less free movement and “spring,”

it might be advisable to set the cutter up only .001 inch.

With experience, the operator learns to “feel” the proper

amount of cutter depth increase to set.

One of the most important factors in good rifling is absolute

uniformity in the passes of the cutter through the bore. After

“setting up,” the first pass in each groove will seem to pull

pretty hard if the cutter is properly sharp and cutting well.

It may not feel as if it’s cutting much on the final pass. The

operator shouldn’t be influenced by this seeming lack of cut-

ting and skip the last pass in an index hole, as the last pass

generally smoothes out some chatter marks from previous

passes. The cutting process continues until the rifling grooves

are of desired depth. Currently, most barrels cut by the hand

rifling process are used as muzzle-loading rifle barrels.

After hand cutting the rifling in a barrel, it’s necessary to

lap the barrel using a lead lap and abrasive polishing com-

pounds. We’ll discuss this process after considering other

rifling methods.

Barrel making is beyond the scope of this course. Therefore,

we intended the previous explanation of handcutting rifle

barrels to instill an appreciation for the work of those who

have brought the art to its present state. Following the given

instructions will enable you to make a hand-cut barrel only

if you have access to a rifling machine, or “bench.”

Broaching

Broaching is another method of barrel rifling. During

broaching, a broach is attached to a steel rod and pulled

hydraulically through the barrel as copious amounts of oil

are pumped through it. The oil serves as a lubricant as well

as carrying out the chips from the cutters.

The broach has several cutters, one for each barrel groove.

Each cutter somewhat resembles a short section of a saw

blade. It has several “teeth” or cutting edges, each about

.001 larger than the cutter ahead of it.

Broaching was the rifling method used for the large majority

of barrels made since 1910, and we still commonly use it.

The process is faster than hand rifling, producing a finished

barrel with one pass of the rifling head.

Rifles30

Rifles 31

The highest grade broach-rifled barrels are finished by

pulling a carbide “burnishing tool” through them after the

broach operation. About .0005 inch greater in diameter than

the rifling broach, this tool has no cutting edges. After lubri-

cating the burnishing tool with grease, you pull it through

the barrel to smooth and compress the bore surface and

rifling by friction. The friction compresses the bore’s mole-

cules of surface steel, which increases strength. A burnished

bore will last longer and, unless it suffers some unusual

imperfection, there’s no need to lap it.

Hammer Forging

The most modern and, in most instances, best method of

rifling, is hammer forging. In preparation for hammer forging,

a carefully ground and polished male core rod, known as a

“mandrel,” is made to the exact size and shape of the fin-

ished rifled bore. The rifling grooves are raised spiral ridges,

and the lands of the bore are depressions between the rifling

grooves.

During the process, the mandrel is inserted into a barrel

blank rough bored just large enough to accept it. Then the

barrel passes through a machine where many automatic

hammers pound it down tightly on the mandrel until it

assumes the shape of the rod with the rifling on it. This

hammering to reduced size compresses the barrel steel and

makes a very fine and tough surface on the inside of the bore

after the mandrel is withdrawn.

Hammer-forged barrels are very long wearing due to the com-

pressed surface of the bore. Also, the rifling is usually more

uniform and smoother since it has been formed on the highly

polished mandrel. Hammer forged barrels require no lapping.

Generally, they are quite stable in their vibration patterns

and very accurate. Some hammer-forged barrels require no

straightening and are the most accurate available today.

Button Rifling

Around 1950, Remington was using a type of rifling called

button rifling. To accomplish button rifling, a gunsmith would

pull, some would push, a preformed hardened tungsten-

carbide swedge through the barrel. With this method, the

rifle would end up with a uniform rifling shape, uniformity in

bore and groove finish, and dimensional uniformity. Button

rifling only took about two to five seconds to complete.

Micro-Groove Rifling

In 1953, Thomas R. Robinson invented a rifling method

called Micro-Groove rifling, used by Marlin (Figure 16). This

method of rifling revolutionized accuracy, giving way to high

bullet velocity and low chamber pressure. The Micro-Groove

design has more rifling lands than the conventional barrels,

which results in engraving on the bullet, giving a secure

spinning grip for stabilization (Figure 17).

The grooves of the Micro-Groove barrel are relatively shallow

and the barrel has a bore that’s greater than standard size.

The shallow grooves and larger-size bore result in a less

grooved and distorted bullet or bullet jacket than conventional

barrels (Figure 18).

Rifles32

FIGURE 16—Micro-Groove Rifling (Courtesy of

Stackpole Books and Marlin Firearms Company)

FIGURE 17—Notice the increased number of landsand grooves. (Courtesy of Stackpole Books and

Marlin Firearms Company)

Rifles 33

Polygonal Rifling

Hechler & Koch (HK) uses a type of rifling called polygonal

rifling (pol i gon al rifling). HK has perfected the polygonal

profile barrel for increased velocity and longer barrel life.

You’ll find the bore of the polygonal barrel to have a rounded,

square, or hexagonal profile (Figure 19). There’s better guid-

ance of the projectile in the bore, which optimizes obturation.

Engraving of the bullet in this type of rifle is considerably

reduced, which increases its service life. Unlike conventional

barrels, the polygon bore traps gas behind the bullet for

increased velocity (Figure 20).

FIGURE 18—The top photo illustrates a conventionally rifled barrel. The bottom depicts a Micro-Groove-rifled barrel.(Courtesy of Stackpole Books and Marlin Firearms Company)

FIGURE 19—The PolygonalRifled Barrel (Reprinted with

permission from HK, Inc.)

Rifles

Lapping

Lapping is an operation performed to renew the surface of

both the lands and grooves and to polish the inside of both

smoothbore and rifled barrels. To lap a barrel, it’s necessary

to first make a lap. A lap is a lead plug that’s poured inside

the barrel so it fits perfectly in the grooves and lands. A cork

with a small hole in its center is pushed down the bore to a

distance about four to six inches below the muzzle.

Caution: Never make a lap shorter than four inches as it will

tend to wear out too fast and not follow the rifling perfectly. I

have read some writers who recommend a lap as short as

one inch. This just tells me they have little experience lap-

ping barrels; otherwise, they would realize the short lap

wears too fast and won’t properly follow the rifling. The long

lap prevents the lap from coming out the breech end of the

barrel. It also prevents skipping index when lapping a barrel

in the closed action.

Next, a cleaning patch saturated with high-temperature

grease is run down to the cork and pulled back out so as to

leave a light coating of grease in the bore. The cork should be

pushed about an inch further down the bore with the greasy

34

FIGURE 20—In the conventionalbarrel (A), the bullet (B) is hid-den in a cloud of escaping gas(C). The Polygonal barrel (D)allows the bullet (E) to trapgas behind it, increasing thebullet velocity. (Reprinted with

permission from HK, Inc.)

Rifles 35

patch and then tapped about the same distance back toward

the muzzle after greasing to avoid leaving an ungreased spot

just ahead of the cork.

Caution: Any ungreased spot in the area where you pour the

lap may result in the lap soldering itself to the bore. If this

happens, you’ll experience great difficulty in breaking the lap

loose from the bore.

An 1/8 inch rod at least six inches longer than the barrel is

fixed into the hole in the cork. I use a long one-piece cleaning

rod with a swiveling handle, which allows the rod to rotate

freely to follow the twist of the rifling. Just above the end of

the rod are several small grooves cut into it with a file. The

end of the rod protruding from the barrel is held central to

the bore and melted lead is poured down the bore until it’s

just below the muzzle.

After the lead cools, it’s tapped with a cleaning rod to break

it loose from the barrel. This shouldn’t be difficult due to the

coating of grease placed in the barrel.

If a lap does become soldered in the bore for some reason,

you can remove it by first heating the end of a rod red-hot

with a torch. Then run the hot rod into the lead and melt it

a bit at a time until it comes loose.

Caution: Never heat the barrel enough to melt the lead. Doing

so might ruin the barrel’s heat treatment.

Warning: When working with hot lead, wear appropriate safety

clothing.

The lap is next pulled out of the barrel on the rod, which was

cast into it. The lap is firmly affixed to the rod because lead

fills the grooves that were earlier filed into it.

Before removing the lap from the barrel, make a mark on the

lap that will align with a tiny mark placed in front of one of

the rifling grooves at the muzzle. This will enable you to

replace the lap precisely into the grooves where it was cast.

When the lap has been removed, it should be oiled with light

machine oil and a patch saturated with light machine oil run

through the bore. Then reinsert the lap in the bore, paying

careful attention to the index mark. Be sure to get the lap

seated back in the grooves it was poured in as there are

small differences both in size and profile in different grooves.

With the lap back inside the oiled barrel, it should be pulled

back and forth until it works smoothly the full length of the

bore. Once traveling freely in the bore, it should be removed

and coated with a fine abrasive. In times past, the abrasive

used was volcanic ash dust known as pumice. Today we use

lapping compounds such as the barrel lapping compound

sold by Brownells or the finest grade of valve grinding com-

pound used on automobile engine valves.

After coating the lap with the abrasive, place it back in

the barrel with the marked groove aligned as previously

explained. Then, work the rod that holds the lap back and

forth through the barrel with long, even strokes. Continue

this process until the abrasive has completely polished the

bore. The process requires removing the lap every 75 strokes

or so and running a cleaning patch through the bore to

remove accumulated dirt and lapping residue from the

barrel and lap.

Also, visually inspect the bore to note progress. If the barrel

has been removed from the action or the breech plug removed

from the bore of a muzzle-loading gun, simply look through

the bore at a light source to inspect it.

Note: You should always remove the breech plug from any

barrel being lapped.

Sometimes it’s expedient to lap a barrel without removing it

from the action. In the case of a bolt-action that allows bolt

removal, it’s easy to observe progress. However, when you lap

a barrel in an action that doesn’t allow straight-line viewing of

the bore, it becomes necessary to use mirrors or borescopes,

which require more experience. If possible, you should prac-

tice finding flaws in a barrel using a borescope to become

more skilled in assessing the progress of bore lapping.

Caution: Lapping should proceed so that each bore section

receives equal attention. If a section appears darker than the

rest of the bore, don’t concentrate on lapping that section

more than any other. Doing so will slightly enlarge the area of

concentration and allow powder gas to bypass the bullet. The

result will be gas cutting the bullet and impaired accuracy.

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It helps to think of lapping as hand-planing a board. When a

section of the board’s surface is rough, it becomes necessary

to bring the entire board down to the rough surface in order

to clean it up. The same applies to lapping the bore. The goal

is to achieve a highly polished uniform diameter and contour.

Lapping should continue until the bore exhibits a uniform

highly shiny appearance without dark or shadowy appear-

ances in any section (Figure 21).

Note: When checking progress, remember to remove the lap

and thoroughly swab the bore with clean patches to remove

the accumulation of lead, lapping compound, and oil. Then,

inspect the bore to determine if further lapping is necessary.

The lapping process should continue until you’re totally sat-

isfied with the job. Prior to resuming the lapping process,

you should wash the lap in a small can filled with solvent

and thoroughly wipe it, thus removing lapping residue and

accumulated abrasive. Also, coat the lap with light oil and

run through the bore to lubricate it. Then coat the cleaned

lap with the lapping compound.

Caution: At all times, use the index mark on the lap to avoid

placing the lap in the wrong grooves. Incorrectly inserting the

lap will damage it, and you’ll have to make a new one.

When the bore reaches the point where it’s uniformly bright,

it’s time to finish lapping with a finer-grade abrasive. I gener-

ally finish lapping with a very fine abrasive such as J-B

Cleaning Compound or X-Bore barrel cleaner. Either product

FIGURE 21—This photo depictsa barrel in a vise in a lappingposition.

provides a really fine finish to the lapped bore, helping to

prevent metal fouling while increasing accuracy potential.

After you’re satisfied that the bore is properly lapped, thor-

oughly clean and wipe it to remove abrasives and lapping

residues.

Caution: Faulty lapping can as easily ruin a bore as improve

it. You should carefully follow the instructions just given to

restore a worn barrel to top-notch accuracy. Improved accu-

racy will bring repeat customers and new customers willing

to pay well for the restoration of their favorite guns to good

shooting condition.

Lapping is especially useful in barrels that have been allowed

to rust; accuracy is lost as a result of buildup of metal foul-

ing in the rusted areas. Lapping is also useful in restoring

barrels that have lost their best accuracy due to erosion just

ahead of the throat section. It’s not possible to completely

remove the eroded portion of the barrel, but it’s possible to

smooth out the eroded section and regain accuracy.

Lapping Shotgun Bores

While this unit concentrates on rifles, the gunsmith can also

benefit greatly from knowing how to lap shotgun bores. Since

most instructions for lapping rifle bores pertain to shotguns

as well, I have included a few extra paragraphs to impart this

invaluable information.

It’s easier to lap shotgun bores since there are no groves to

fill and the lap plug moves much easier through the bore.

However, in a choked barrel, the lap must be poured in the

section of the bore behind the choke. It won’t work in the

tapered section of the choke. I know one gunsmith who claims

he pours the lap right up to the muzzle and it works fine.

This has not been my experience. You don’t need to use an

index mark on a shotgun lap as it will be rotated in polishing

the bore. However, the lap must be removed from the breech

for cleaning and oiling, as it won’t pass the choke section.

The best method I know for restoring a shotgun barrel is to

pour a lead lap below the choke section and attach it to a

rod with deep grooves cut into it to hold lead. A swiveling

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arrangement isn’t necessary, as the lap should be rotated in

a shotgun bore. The lap can be attached to an electric hand

drill and run back and forth in the bore while the drill

rotates it. This allows for very fast cutting and restores the

barrel quickly.

In the choke section, use a wooden dowel that’s slit with

a hacksaw for a short distance. Wrap a fine-grade emery

cloth—emery side against the bore—around the dowel, and

attach it by inserting the ends in the slot cut in the dowel.

You can oil this emery cloth and spin it with the electric

hand drill to quickly polish the choke section.

You can polish the choke section using cotton bore oil of the

proper gage to which a liberal amount of lapping compound

has been applied. Again, the cotton bore oils are spun with

a hand drill.

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Self-Check 3

Indicate whether the following statements are True or False.

_____ 1. Alluminum barrels with steel liners were unsuccessful because the light weightallowed too much vibration.

_____ 2. SAAMI specifications were set up to furnish a standard to which all American manufactured arms and ammunition could be compared and as a standardizationsystem for the formerly chaotic manufacturing tolerances of the firearms industry.

_____ 3. A shorter barrel is required for overbore cartridges.

_____ 4. A burnishing tool works by compressing and soothing the bore surfaces.

_____ 5. The barrel weight of a rifle isn’t important to it’s accuracy.

Check your answers with those on page 129.

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BARREL STEELS

To teach barrel making is beyond the scope of this course.

However, we’ll discuss properties of various barrel steels that

will help you select the proper barrel blank for your cus-

tomers’ rifles.

Today, barrel manufacturers use four general categories of

steel:

• Black powder, or gun barrel grade, carbon steel

• Ordnance, or high-power carbon, steel

• Nickel steel

• Stainless steel, often known as rustproof steel

The four general categories encompass many different trade

names used by various barrel makers. Each barrel maker

claims certain superior advantages for its barrels and there

are some differences. However, the steel used in making a

barrel, provided it’s the proper strength, isn’t nearly as

important as the methods and quality of workmanship used.

Black Powder, or Gun Barrel Grade,Carbon Steel

Black powder carbon steel is relatively soft, plain carbon

steel. After wrought iron passed from the scene, manufactur-

ers used this steel for building black powder rifles. Its use is

now limited to barrels intended for muzzle-loading rifles and

other loadings that won’t generate over 25,000 pounds per

square inch. Black powder steel doesn’t have the tensile and

shear strength to withstand modern high-power cartridge

loadings, which generate pressures in excess of 25,000

pounds, but it’s acceptable for rimfire .22 caliber barrels.

A few years ago there were serious problems with some steels

used in imported black powder muzzle-loading rifles. The

problem was that foreign black powder barrel makers used

extruded steel to which a significant amount of lead was

added to facilitate the extrusion process. The steel was

extruded as the finished outside of the barrel with a hole

through its center.

The hollow center enabled the barrel to be made with minimal

machine work. First, a reamer was run down the extruded

bore to clean it up abit. Then a rifling broach was pulled

through the bore. This quick-and-easy process made it

possible to produce barrels very inexpensively.

However, the weakening effect of the lead and the arrangement

of the steel’s grain caused by the extrusion die caused prob-

lems. As it turned out, aligning the steel grain lengthwise

along the axis of the barrel resulted in good linear strength,

but unbelievably poor hoop strength. This caused quite a few

barrels to burst or “goose egg” (swell in a barrel section) with

loads that should have been perfectly safe. This situation

continued until some of the more knowledgeable black powder

shooters and writers made enough fuss to get it corrected.

Note: Many sections of burst muzzle-loading barrels are still

scattered around the hills near my test site here at Falling

Waters, WV (Figure 22). This is the result of a series of proof

tests done for a black powder magazine on suspect barrels,

which blew with only moderate proof loads. At the other

extreme, barrels made by several manufacturers withstood

very heavy proof loads without incident. Getz, Green

Mountain, and Thompson Center barrels required heavy

loads of fast-burning smokeless shotgun powder to burst

them during the destructive testing phase.

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FIGURE 22—Shown is a sec-tion of a burst muzzle-loadingrifle barrel. Failure to properlyseat the ball caused theaccident.

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Other reputable manufacturers such as Lyman and Navy

Arms also made good strong barrels through this period.

The gunsmith should have no qualms about using these

companies’ products. After the appearance of a series of

magazine articles concerning the problems engendered by

inferior barrels, the situation rapidly cleared up. To the best

of my knowledge, all rifle and most other barrels being sold

presently in the United States and throughout North America

are of a good-grade homogeneous steel.

Ordnance Steel

Ordnance steel, or high-power carbon steel, is the type used

in most gun barrels intended for use with today’s high-power

cartridges. While the composition of ordnance steel varies

among manufacturers, it usually contains additives in the

following amounts.

Manganese 1.00%–1.30%

Carbon 0.45%–0.55%

Phosphorus (maximum) .05%

Sulfur (maximum) .05%

The majority of high-power rifle barrels made in recent

decades are composed of ordnance steel. A few of the larger

manufacturers who used ordnance steel in their barrels are

Remington, Savage, G.R. Douglas Barrels, and Springfield

Armory.

Names for ordnance steel have changed in the last few years,

with many firms claiming to have different new steels.

Frankly, I don’t find much difference as far as machining

properties and other characteristics are concerned. As this is

a carbon steel, it’s usually heat-treated. Variations in work-

ing properties as well as tensile and shear strength are con-

trolled by the heat treatment. Therefore, you must avoid

overheating this steel unless you intend to heat treat it after

your work. Also, heat treatment is a process that requires

high-temperature furnaces and solid knowledge of a subject

that’s beyond our scope.

Nickel Steel

The Winchester Repeating Arms Co. and some other barrel

manufacturers use nickel steel. Rock Island Arsenal, Niedner

Rifle Corporation, and most British rifle makers are among

the larger users of nickel steel.

Nickel steel is also popular with custom barrel makers, as

many shooters desire its ability to withstand bore erosion as

well as its improved corrosion resistance. Nickel steel is a

very fine barrel steel with many highly desirable qualities.

While it’s not a “stainless” steel, it does have superior protec-

tion against rust, due to its three percent nickel content.

High-power carbon steel seems to wear faster than nickel

steel and is very susceptible to rust. Nickel steel runs

.030–.040 carbon. It’s an acid open-hearth process steel.

Many think open-hearth steels, due in part to oxygen expo-

sure at high temperature, have more resistance to corrosion.

Nickel steel is more difficult to blue than ordnance steels, and

when it is, the bluing seems to wear off faster from handling

than other type steels. Many of us can remember Winchester

Model 12 shotguns and Model 70 rifles belonging to our

fathers and grandfathers. Their almost silvery color was the

result of the bluing wearing off after many hours in the field.

Stainless Steel

Stainless steel is also known as Rostfri, Rust-Proof, Anticoro,

and Antinit steel. Apparently, these “stainless” steels are the

wave of the future, at least in the better grade of higher-

priced barrels. Much of this steel is imported from Austria,

Germany, and Sweden. Technically, they’re not actually

steels; instead, they’re high-chrome iron. The exact formulas

and manufacturing processes are proprietary secrets, closely

guarded. Recently, there have been some American-made

stainless steels used in gun barrels, and these seem destined

to fill a larger portion of the gun barrel market. Again, the

exact composition and manufacturing processes are propri-

etary, but their compositions are basically about 14 percent

chromium, 0.10 percent carbon, and 1.50 percent copper.

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Stainless steels are very difficult to machine and wear even

carbide cutters very rapidly. Chromium steel is abrasive due

to its hardness factor. I’ve heard that the copper is added to

increase machinability, and I know that these steels are put

through very complex heat-treating processes to attain the

level of machinability they do have.

Even stainless steels aren’t actually rustproof, which I learned

the hard way by making a muzzle-loading barrel from Inconel

stainless. I hoped to eliminate the messy process of washing

out the bore with soap and water, wiping it dry, and oiling it

after a thorough drying. If you have a muzzleloader, you’ll

understand what one goes through to clean it after a day of

shooting. My new stainless steel barrel, which I so painstak-

ingly made and polished, rusted over a period of time from

the acid and other residues of black powder. It rusted much

more slowly, but it did rust.

To the best of my knowledge, a truly rustproof steel does

exist for black powder use. This is a fairly soft metal, not

exactly steel, known as “Monel.” Monel isn’t strong enough for

any barrel use except black powder. Even so, it’s only mar-

ginally strong enough for even the lightest loadings in wall

thickness that shooters can conveniently carry. Furthermore,

Monel is so difficult to machine that I wouldn’t make another

barrel from it for 10 times the price!

Monel’s lack of yield strength requires a heavy-walled barrel,

which is too cumbersome to carry comfortably in larger cal-

ibers. As a result of a test I performed, I say it lacks yield

strength. I tested a section of Monel tubing with a .375 bore

and .750 outside diameter, which would be considered heavy

enough for a muzzle-loading barrel of ordinary steel. When

fired with patched .370 ball in front of 90 grains of FFFg

black powder, it swelled up in a goose egg! While it didn’t split

or burst, it would have ruined any stock if inletted. Actually,

the load wasn’t even a proof load. At a light proof load of four

grains per caliber, 150 grains would be considered a proof.

The tube failed at 60 grains below proof! Furthermore, this

“smoothbore” had not been subjected to the weakening

effects of rifling grooves.

Had the Monel tube withstood proof loading and further

testing with double-charge, double-ball proof loads, it would

have been rifled and further pursued. As it failed initially,

there was no reason to continue the experiment further.

Stainless barrels are difficult to machine, complex to heat-

treat, expensive, and difficult to blue or brown. Therefore, I

don’t recommend becoming involved with them except when

purchasing and installing finished, ready-chambered, barrel

blanks. Even then, I recommend involvement only if you have

a lathe set up to handle precise shouldering in tough, hard

steels. Adding or removing a turn of threads to maintain

headspace with stainless steel barrels is a different class of

work than the same operation on an ordnance steel barrel.

Even if your shop is equipped for rebarreling with stainless

steel, the difficulty of bluing or browning it remains. The

method most commonly used for bluing is to electroplate the

stainless barrel with black nickel. Stainless barrels can also

be electroplated with soft iron and blued using hot salt bluing

processes; or they can be copperplated, and the copperplating

chemically blackened to form an acceptable appearance.

Modern shooters are beginning to accept bright polished

stainless steel barrels, but they’re not suitable for hunting.

The bright shine and flashes of light from the barrel alert

game to the hunter’s presence.

The purpose of discussing stainless steel isn’t to discourage

the gunsmith who’s equipped for stainless steel barrel work

from trying it. By all means, try it on one of your own actions

in a chambering you can personally use. Then, consider fur-

ther work. My intent is to forewarn you about possible diffi-

culties of which you should be aware.

Installing a Barrel on an Action

Often a customer will bring in a rifle with a barrel that for one

reason or another has been ruined. The most common cause of

a bad barrel is failure to clean it after shooting. Most shoot-

ers start out their shooting experiences with .22 rimfire rifles.

The .22 rim fires, with the exception of the .22 Winchester

Magnum, use greased lead bullets. The greased bullets leave

a coating of grease on the bore that acts as a rust inhibitor.

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So, it’s not necessary to clean such guns after every day of

shooting to prevent rust. Most shooters just clean them occa-

sionally to remove accumulated lead and grease. This works

well enough for an inexpensive .22 plinker, but you should

always clean a gun after shooting it.

In any event, problems arise from shooters who assume they

can get by without cleaning their high-power rifles after every

shooting session. This just won’t work with high-power rifles

that don’t use greased bullets. The intense heat and pressure

inside the barrel vaporize any cleaning oil remaining from the

previous gun cleaning. The bare, dry bore quickly rusts from

residual atmospheric moisture. Within a few months of not

being cleaned after firing, especially under such high-humidity

conditions as are found in the Southern and Eastern United

States, the barrel rusts beyond restoration, even by lapping.

The easiest way to get the customer’s gun working again is

to order a new barrel from the manufacturer, remove the old

barrel, and install the factory replacement. This eliminates

a lot of problems, as the barrel will have the right threads and

the contour will fit the stock. All you have to do is remove

the old barrel and replace it with the new barrel. This proce-

dure requires certain skills. First, you must fit the barrel

properly to the action. Then it must be correctly headspaced.

We cover chambering and headspacing in the next study

unit. Following is an inexpensive method for removing and

installing a barrel on an action.

Removing the Old Barrel

You can remove a threaded barrel from an action easily with

simple tools. Assuming that you already have a heavy bench

vise, you’ll need

• Two small blocks of hardwood

• A pick handle (or baseball bat)

• A 15 foot piece of 1/2 inch nylon rope (silk rope is even

better)

• Some rosin—the type used on violin bows is fine

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First, cut two hardwood blocks to the rough shape of the

action. Place the barreled action between these blocks and

tighten them in the vise.

Note: In this example, the muzzle should

extend out to the left of the vise (Figure 23).

Then, liberally sprinkle rosin on the rope,

fold it in two, and hold its open ends against

the barrel with your right hand.

Note: You should replace the open ends

about midway down the barrel pointing

toward the breech. The looped end should

extend past the muzzle.

Next, with your left hand, wind the looped

end of the rope around both the barrel and

the rope already resting against it. Begin at

the muzzle and lap the rope over the barrel, pulling it back

toward you from under the barrel.

Note: Getting the overlap started takes a bit of practice, but

you’ll quickly get the hang of it. Especially when beginning

the lap, hold tension on the rope to prevent it from coming

loose. Wind up all of the rope but the remaining loop, and

be sure to leave the open loop big enough to insert the pick

handle.

Place the pick handle in the loop and begin to tighten it.

You’ll be pushing the handle over the barrel and then pulling

it towards you. The object is to tighten the rope against the

barrel, thus creating counterclockwise force.

Note: With your left hand, hold the rope tightly at the muzzle

end to prevent slack.

Once the rope is sufficiently tight, the rosin will grab the

barrel and the wooden handle will act as a lever to rotate

the barrel out of the action’s right-hand threads.

Installing the New Barrel

A new factory barrel should screw into the action fairly easi-

ly, up until the last quarter turn or so when it should begin

to tighten up. Wind the rope around the barrel in the other

direction to tighten it into the action. Turn the barrel tight

48

FIGURE 23—Illustrated Barrel Removal Procedure

Rifles 49

until the index marks on the action and barrel line up. In

some instances, you’ll have to insert a thin shim in front of

the barrel shoulder if it turns past the index mark before

tightening up. Conversely, some barrels will tighten up

too soon. You might have to take a tiny slice off the barrel

shoulder—not more than .005 inch at most. Align the index

marks to ensure that the sight slots are square and that the

barrel properly aligns with the action.

Caution: Never face any metal off the front of an action to

allow barrel index mark alignment. I’ve seen evidence of this

work performed by so-called gunsmiths whose interest lies

more in making money than doing good work. Facing metal

off the front of the action permanently alters its alignment,

and any future rebarreling of the action will be very difficult.

Selecting Barrels

When you set out to select the proper weight and contour for

a barrel to install on a customer’s rifle, many considerations

come into play (Figure 24). First, there are customer desires.

Does the customer want a lightweight rifle, a field weight

hunting rifle, a varmint weight barrel, or perhaps even a

bull barrel?

After determining the customer’s wishes, you must consider

the balance of the rifle. The balance point, except in a bull

barrel, should be just in front of the trigger guard. It can

vary a couple of inches from this point, but anything over

FIGURE 24—This drawing depicts barrel contours.

this is going to feel either muzzle light, or muzzle heavy.

Therefore, you must consider the weight of the action and

the caliber of the bore. Given the same outside contour and

length, a .22 caliber barrel is going to be somewhat heavier

than a .30 caliber barrel, and a lot heavier than a .44 caliber

barrel the same size. Except for target shooters and varmint

hunters, no one wants to add weight to a rifle. Considering

that the barrel weight counterbalances with the weight of the

action and buttstock, keeping the balance point in the right

place severely limits the options for barrel contour. Many

beginning gunsmiths forget these factors and end up with

ungainly, clumsy-handling, out-of-balance rifles on their first

try at rebarreling.

Using the Springfield 1903A3 action as an example, a .30

caliber barrel will have a straight section 1.140 inch diameter

from the shoulder to a point 1.250 inches ahead of the

shoulder. Then it will go into a straight taper from the 1.140

inch diameter front end of the straight section to a diameter

of .955 inch over the next 1.750 inches. From the .955 inch

diameter, it will have a straight taper to around .648 inch at

the muzzle to fit standard sight bands. Obviously, the taper

will be faster and the barrel lighter if it’s cut off at 22 inches

than it would be if it were left 26 inches long.

Back in the days when we could obtain a good Springfield

1903A3 for $15.50 plus $3.00 shipping, a grand total of

$18.50 for this splendid rifle, gunsmiths were busy “sporter-

izing” Springfields. Sporterizing generally consisted of cutting

the barrel off to 22 or 24 inches, turning the barrel lightly to

smooth it up. Then you replaced the stock with a “sporter”

style stock from Reinhart Fajen, Bishop, or Herters, who

supplied nice stocks pre-inletted for Springfield actions and

standard contour barrels as dimensioned above. Usually, the

gun was reblued, and drilled and tapped for scope mounts.

After the metalwork had been completed, a hole was drilled

into the buttstock under the buttplate. This was done to

lighten the butt section if the balance point was too far to the

rear, or a bit of lead was inserted in the forend to move the

balance point forward. Suppose the customer insisted on

keeping a muzzle-heavy rifle as light as possible. Then, a

faster taper would be turned on the barrel from the end of the

taper in front of the straight receiver section to the muzzle.

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Otherwise, a piece of lead would be inserted in a hole under

the buttplate.

The heaviest rifle barrels intended for “offhand” shooting,

given a 1.250 inch diameter over the chamber, would carry a

straight taper from the front end of the cylindrical 1.75 inch

length at the chamber, to around .880 inch at the muzzle.

This taper provided about as heavy a barrel as a shooter

could hold up offhand and maintain accuracy.

Most hunting rifle barrels have a muzzle diameter of .647

inch to allow for front sight bands such as those used on

the ‘03A3 Springfield. Even if you don’t plan to use a barrel-

band type sight, it’s good to consider using a standard muzzle

diameter so you can fit the sight of your choice. Often front

sights are “sweat” soldered onto the muzzle. Such installations

allow for a bit of circle diameter tolerance. Still, to properly

install the sight, consider which barrel diameter sights are

available before finishing the muzzle diameter to a size that

requires boring a sight base radius. You can avoid this time-

consuming job by using a standard sight base radius as the

final muzzle diameter.

As previously mentioned, 22 to 24 inches is the standard

length barrel for high-power rifles in the medium calibers,

although most gun makers like to use 26 inches for the

heavy calibers such as the .300 magnums and .375s. Muzzle

flash and blast become more unpleasant as barrel length

decreases, and even though velocity loss is slight with short-

er barrels in these calibers, they’re unpleasant to shoot. If a

customer insists on a .375 magnum carbine with an 18 inch

barrel, make sure he or she understands that shooting it

won’t be an enjoyable experience. Place in writing that you,

as a gunsmith, advise the customer of the problems encoun-

tered by such a short barrel. Then, if you end up with an

unhappy customer, you won’t be stuck with an unwanted

gun.

Of course, you must consider power as well as the bore

diameter when determining the minimum diameter and

length of a barrel. Low-powered rounds, such as the .25-20,

may be of much smaller diameter and length without either

excessive muzzle flash and blast, or severe impairment of

accuracy. Using good ordnance steel, a .22 rimfire barrel may

be made as small as .580 inch at the breech and .375 inch

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at the muzzle without danger of being damaged from the

pressure of the loading. Such a barrel wouldn’t be as accu-

rate as a stiffer, heavier barrel due to barrel vibration.

Turning Down Barrels

Customers will often ask the gunsmith to turn down barrels

to make them lighter. If you have sufficient metalworking

experience and a lathe, this could earn you some money.

However, you must prepare for the turning to release stresses,

which will cause the barrel to bend regardless of how careful

you are. When this first happened to yours truly, I assumed

that I had somehow inadvertently bent the barrel.

It was a Springfield barrel I had mounted with a driving dog

on the action flat and a plug the size of the bolt with a center

in it fitted on the face plate and center of the engine lathe.

It was wobbling in the lathe, and I was afraid I was going to

have to replace the barrel. In an effort to straighten the bar-

rel, I placed a steel bar under the tracer attachment bar.

I then used it as a lever to bend the barrel back straight so

I could finish turning the barrel. Using a dial indicator, I was

able to true the barrel within two thousandths of an inch and

continue turning until it again warped and started wobbling

against the cutting tool.

I eventually learned to go ahead and finish turning barrels

(unless they went so far out as to make an interrupted cut)

and then straighten them when I had finished. If they go too

far out, I have learned to tap them reasonably straight with a

lead mallet and then straighten them properly after turning.

Barrel Straightening

This brings us to barrel straightening, a very difficult process

requiring great expertise, regardless of what some would

have us believe. I don’t recommend the process unless you

gain hands-on experience working under qualified supervi-

sion. However, I overview the task briefly in the interest of

further knowledge. In brief, I accomplish barrel straightening

by placing the barrel across two heavy steel fingers and

applying pressure to it between the support points so as to

bend it the necessary amount.

52

Rifles 53

To judge straightness, I point the barrel toward a window

with a dark bar across it. I straighten the barrel by looking

through the barrel at the shadow of the bar in the window,

and by bending the barrel until there are no offsets or curves

in the shadow of the bar in the barrel.

Recoil Compensators

Recoil compensators reduce recoil by directing the energy

of the gases in the barrel against a shoulder or series of

holes at the muzzle. The gases drive forward on the barrel

in opposition to the recoil. There are two basic types of recoil

compensators, with many variations of the basic types.

One type is a series of holes or slots milled into the barrel at

the muzzle. The other type is an attachment that’s screwed

or sweated (soldered) onto the muzzle (Figure 25).

Each type of recoil compensator has advantages and disad-

vantages. The screw-on type is difficult to install unless you

have a lathe to turn down or thread a short section of the

muzzle on which the compensator is installed. Whether

threaded or sweated in place, the compensator must be

exactly true with the axis of the bore if the rifle is to shoot

accurately. Any misalignment will cause different gas pres-

sures to bear on the bullet and deflect it from its true course.

FIGURE 25—A Shal-Cut Muzzle Brake Mounted on a .300 Weatherby Rifle

If you’re installing a threaded recoil compen-

sator, first determine the thread size and

pitch. Then, if at all possible, cut the threads

onto the proper length of threaded area at

the muzzle. If the barrel is centered in a

lathe that has a live (revolving) center, set

a centering plug into the muzzle. You can

easily make a centering plug by turning the

shank of a properly sized bolt (3/8 inch will

do for most rifles of .25–.35 caliber) to a

point where it will just fit nicely in the bore

of the barrel (Figure 26).

Cut a relief groove at the base of the head to ensure that the

bolt head seats squarely on the muzzle of the gun. Center the

head of the bolt using a 60° center drill and insert the plug

into the bore at the muzzle to support it during machining.

Then, cut the threads onto the barrel. The compensator will

be true to the bore, and no problems will arise.

It’s a timesaving idea to cut the threads down to within a few

thousandths of an inch of the finish pitch diameter of the

threads and then run a die down over the threads to finish-

size them. This is much less time-consuming than cutting

the threads to finish size.

After cutting the rough threads, remove the barrel from the

lathe and carefully start the die onto the cutting threads to

finish-size them.

Note: If your lathe isn’t set up to cut threads, you can center

the barrel in the head stock and remove the center from the

tail stock. Turn the thread’s maximum diameter on a short

section of the muzzle. Then use the face of the tail stock as a

guide to hold a die square with the barrel and run the die the

desired distance down the barrel. Be careful! This method

might result in threads that aren’t entirely square with the

barrel and might cause accuracy problems.

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FIGURE 26—This drawing depicts a lathe centerplug for a muzzle.

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You make the second type of recoil reducer by cutting slots

or holes into the barrel near the muzzle. The holes are angled

to the rear about 10° to direct the gas to the rear and coun-

teract recoil. The problem with cutting such slots and holes

is that any burrs or rough edges that remain inside the bore

will severely impair accuracy.

When you use a barrel-porting recoil reducer, you cut the

holes in the barrel with an electronic discharge machine (arc

borer), which works on the same principle as an arc welder.

The electronic discharge machine erodes metal under arc

and makes a perfect cut, leaving no burrs. The actual cutting

tool is a carbon rod that carries an electrical charge from an

arc welder and “eats” the metal away by electric sparks as

you move it into the barrel. This method doesn’t cause any

burrs or roughening of the bore. The barrel porting system

doesn’t add length, diameter, or weight to the barrel. The

most popular process for barrel porting is patented by

Magnaport International.

Note: I recommend that you send customer rifles to

Magnaport to have the barrel-porting recoil reducer work done

and charge a fair markup. Magnaport has the specialized

jigs, fixtures, and tools to do the job correctly. These tools are

far too expensive for the individual gunsmith to buy due to

the relatively few jobs that will come your way. It’s important

to realize that a professional often gets paid for his or her

knowledge as well as actual work. In this instance, knowing

where to get the job done correctly is worthy of profit.

Flash Suppressors

Flash suppressors are metal tubes attached to the muzzles of

guns to keep the muzzle flash from being visible to the

enemy during combat or similar situations. They can hide

the flash from all directions except the position in front of the

bore. Flash suppressors can be made from a section of thin-

wall tubing that’s soldered or threaded onto the muzzle using

an adapter to fit the muzzle (Figure 27). They work on the

principle of having a large enough shielded chamber to con-

tain the muzzle flash. There’s not much interest in them

except by those who are into military collecting and want to

have an authentic-looking weapon.

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FIGURE 27—Flash suppressors are available in several styles. (Drawing courtesy

of David Capobianco Co.)

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Self-Check 4

Indicate whether the following statements are True or False.

_____ 1. Recoil compensators work by directing some of the gas against a series of holes or slots in the compensator to allow the force of the gas to push the barrel awayfrom the shoulder.

_____ 2. Using stainless steel in a gun barrel eliminates the need to clean the gun as it willnever rust.

_____ 3. Extrusion is a good method to use in making barrel steel.

_____ 4. In turning a barrel, the muzzle should be centered on a live center running on a pluginserted in the muzzle.

_____ 5. Barrel straightening is accomplished by running the barrel under a dial indicator andbending until the indicator reads true along the full length of the barrel.

Check your answers with those on page 129.

TRIGGER MECHANISMS

Triggers and sears can be the most sensitive and dangerous

parts of a rifle. Accordingly, trigger work is an advanced skill

best left to those with specialized hands-on training and

extensive experience. Due to the danger of accidental discharge

resulting from a malfunctioning trigger and the potential for

liability, a growing number of manufacturers refuse to sell

replacement parts for triggers to anyone, including professional

gunsmiths. Manufacturers don’t want gunsmiths to perform

trigger work. Instead, they urge gunsmiths to send guns

requiring trigger work back to the factory for service. Some

manufacturers even conduct armorer schools where students

train specifically to repair the manufacturer’s firearms

(including trigger mechanisms). A student who successfully

completes such training can then obtain a license to do work

by the manufacturer.

Warning: You must weigh the dangers associated with doing

trigger work, the potential for liability, and the high cost of

insurance—much higher than for other gunsmithing tasks—

before you take in this type of work. Furthermore, unless you

have access to hands-on instruction from a professional, you

must gain sufficient experience by training yourself on your

own firearms. Considering these factors, I strongly advise you

to turn down all trigger work.

Anyone who has tried the trigger pulls on rifles made in the

last few years is well aware that rifle manufacturers are also

running scared for fear of accidental discharge and resultant

legal complications. The trigger pulls of new rifles have gone

from comfortable 25–40 ounce pulls to stiff, difficult-to-shoot

100–150 ounce pulls. The latter are almost impossible to

shoot accurately from an offhand position, and competent

shooters are almost sure to bring their new rifles in to have

such atrocious pulls corrected. You must develop your own

policy for such situations and stick to it.

Also, there are situations where a trigger mechanism breaks

or becomes worn to an unsafe condition. All too often, a

“basement gunsmith” renders a trigger mechanism unsafe

due to either ignorance or foolishness, and sometimes trigger

mechanisms become inoperative as a result of faulty or broken

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parts. Such situations are difficult for the gunsmith. One

cannot realistically expect to discard an entire rifle because

of a broken or maladjusted trigger, and the customer may

argue his/her case well.

In another situation, a good customer may insist on your

making the 10 pound trigger on a newly purchased rifle into

a shootable 2 pound pull. Since your customer bought the

rifle from you, he or she may insist that you adjust the pull

or lose a customer. The customer may feel that it’s your duty

to make the rifle shootable. In a situation where no mechani-

cal problem exists and the customer “pleads” for your help,

you might begin to weaken.

If a good customer “twists your arm” and convinces you to

do work on a trigger mechanism, at least follow these simple

rules.

• Don’t do any trigger work until you’ve had sufficient

hands-on training and know what you’re doing.

• Never drop a pull below minimum factory specifications.

• Don’t perform any work that will compromise a firearm’s

safety.

• By all means, carry liability insurance.

• When possible, improve trigger pull by installing after-

market assembly designed to produce the type of pull

the customer wants.

Trigger Adjustment

Many rifles have adjustable triggers that allow adjustment of

the depth of sear engagement and the spring tension.

Rifle triggers that have no adjustment are usually the simple

sear-and-hammer type, such as the notch sear of the

Winchester Model 94, and many other rifles having hammers

with cut sear and safety notches. The trigger used in the

Winchester M 67, Springfield 03–A3, and a myriad other

rifles have slightly different sears that operate on the same

principle. Such a trigger, regardless of what action it’s on,

can be improved by carefully stoning the sear to smooth it

(Figure 28). When stoning a sear, make it to engage

across the full area of the notch or bar to reduce

friction and wear. Reduce friction by distributing

the load over a wider area with less pressure at any

given point.

If there’s slightly excessive engagement that causes

creep, carefully stone the sear to reduce engage-

ment to a safe point.

Note: Creep is movement of the trigger before it “breaks,”

which is the term for the point at which a trigger releases the

sear and fires the rifle.

If there’s a deep overengagement, the best policy is to drill a1/16 inch hole in the hammer or sear bar at the point where

the sear engages. Then, insert a short section of a 1/16 inch

diameter nail into the hole (Figure 29). The sear will strike

this nail, which will eliminate overengagement. Then file the

nail until you attain proper engagement.

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FIGURE 28—Pictured is a Hard ArkansasSlip Stone for stoning sears and triggernotches.

FIGURE 29—Rotating hammerand simple sear type triggerassembly showing how toinsert a pin to control thedepth of sear engagement.(Drawing courtesy of David

Capobianco Co.)

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You must not change the angle of the sear or sear notch

unless you have to decrease the angle to eliminate the sear

having to cam the hammer or striker back to disengage. If

you must remove this much metal, you should use a fine cut

Swiss Grobet needle file. Be careful not to remove too much

metal or to decrease the angle too much.

Normally, such sear work is done by honing, which requires

a fine grade of hard Arkansas stone with a knife-edge made

especially for such operations as stoning trigger notches and

sears. Hold the sear or notch in a secure position where you

can set the stone at the proper angle and gently hone the

required surface. Often a simple stoning and polishing,

which smoothes up the engaging surfaces, will suffice to

lighten a heavy pull or take the drag out of a rough one.

Another problem often encountered while trying to develop

good trigger pull is that the sear is too soft to slide easily

against the hammer. This can be remedied by case-hardening

the sear.

When removing substantial amounts of metal from sears, it’s

common to remove the steel’s case-hardened surface. This

situation also calls for rehardening.

Warning: If a trigger’s sear engagement fits into the hammer’s

half-cock notch on the end of the trigger, don’t file the sear

so short that it doesn’t bottom out in the half-cock notch.

Suppose the sear end of the trigger wedges into the half-cock

notch of a rifle with a solid tool steel hammer. The half-cock

notch might break off from metal contraction if you set the

gun in the half-cock position in warm conditions and then

take it into near-zero temperatures. This is very dangerous,

as an accidental discharge can occur. The sear must bottom

out in the half-cock notch as shown in Figure 29.

Removing Two-stage Triggers

Other trigger work concerns removal of two-stage triggers from

military rifles such as the Springfield and the ‘98 Mauser.

You can use many methods to accomplish this worthwhile

end. I prefer to drill the sear bar and tap the hole for a #6–48

screw. I then adjust the screw to the desired sear engagement

and lock it with a #6–48 locknut. This will gave you a nice,

easily adjusted trigger. You can also use a short piece of a

nail or pin, but you can’t easily adjust the nail (or pin).

Whenever possible—as when working on military rifles that

have a sear bar and room for an adjustment screw—use an

adjustment screw.

Aftermarket Triggers

Aftermarket triggers are available for many of the more

popular rifles. Timney and Canjar are just two aftermarket

trigger manufacturers whose products have given me com-

plete satisfaction. Several other makes are available, and I

have heard good reports on most of them. Available in many

different types and models, aftermarket triggers are particu-

larly useful for replacing Enfield, Springfield, and Mauser

triggers when these military rifles are converted to sporting

rifles. Installation is simple. Just faithfully follow the instruc-

tions that come with the triggers. Some aftermarket triggers

fit several different models and the rifle and/or trigger often

requires grinding and filing to obtain proper fit.

Aftermarket models available include single triggers that

work just like the original triggers, simply pulled to fire the

rifle. Their advantage is that they’re adjustable to whatever

weight pull the shooter desires and have a clean, crisp break

without creep or overtravel.

Note: As mentioned, creep is movement of the trigger before

it “breaks,” which is the term for the point at which a trigger

releases the sear and fires the rifle. Overtravel is rearward

movement of the trigger after it breaks. Overtravel can be a

problem as the sudden release of tension on the trigger finger

can cause the gun to lift in the shooter’s hands and shoot

high. A good trigger shouldn’t give much evidence of moving

before it breaks and shouldn’t have any noticeable movement

after breaking. This helps the shooter maintain a proper hold

as he or she fires the rifle.

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Set Triggers

Set triggers are also helpful in maintaining a steady hold

when firing. Two basic types of set triggers are available, with

variations on each type. The most common type is the double

set trigger, which is actually two triggers, one behind the other.

Usually the front trigger is the “set” trigger; the rear trigger

is the “setting” trigger. When you fire a double set trigger,

the setting trigger is pulled first until it clicks to indicate that

the set trigger is ready to be fired. When the setting trigger is

pulled, a weight (sometimes called a fly bar) is pulled down

against a spring, and latched onto the front of the set trigger.

The set trigger has a very light setting, often only a few

ounces. When pulled, it releases the fly bar, which springs

up and knocks the sear out of the notch, thus firing the gun.

There are various mechanical differences in the double set

trigger, but the general principles involved are the same.

The second type of set trigger is the single set trigger. This

type has only one trigger. The trigger is first pushed forward

until it clicks to set it. Then it’s pulled in the normal manner

to fire the gun. This type is rather touchy and hard to adjust.

Once either type of set trigger has been set, it will work with

equal ease to fire the gun.

Note: Both types of set triggers will fire the gun from an unset

position; however, the trigger pull will usually be very heavy

from the unset position.

As stressed early on in this section, if you choose to perform

trigger work, you should exercise the utmost care in installing

and adjusting triggers. You shouldn’t set the trigger, for

example, below a 12 ounce pull until the shooter has become

very familiar with its operation. Discourage the shooter from

regulating the weight of pull.

Finally, before performing trigger work or any other work on

a firearm, you should have the factory manual for it in front

of you as a reference/ study guide. If the exact manual isn’t

available, carefully study the manual for a similar gun. Never

rush blindly into tearing a gun apart.

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Self-Check 5

Fill in the blanks in the following statements.

1. _______ is the movement of the trigger before it “breaks.”

2. A simple hammer-and-trigger type sear should bottom out in the _______ notch.

3. Prior to performing any trigger work, you should have sufficient hands-on training as wellas _______ insurance.

4. The _______ trigger mechanism is a good answer to the gun that doesn’t have a goodadjustable trigger.

5. A trigger or sear that’s too soft is dangerous and should be _______.

Check your answers with those on page 130.

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FIREARM FUNCTIONS

The heart of any firearm is the action, which consists of the

arm’s moving parts and housing. We usually call the housing

the receiver, into which the barrel is threaded or otherwise

locked. In all guns, except the blowback-type action, the

action accomplishes eight functions.

Feeding. The act of positioning the cartridge, usually by

the magazine, in line with the chamber in preparation for

chambering (Figure 30).

Chambering. Movement of the cartridge into the chamber

(Figure 31).

Locking (of cartridge in chamber). Depending on design,

the cartridge is locked in place, or chambered, simply by

closing the lever or bolt action or, with autoloaders, by letting

the slide spring forward.

Cocking. Cocking results in compression of the firing pin

spring and is accomplished by opening or closing the lever

or the bolt; or automatically, by autoloaders, on the second

and following shots.

Firing. Applying pressure to the trigger to release the

firing pin.

FIGURE 30—Feeding FIGURE 31—Chambering

Unlocking. Unlocking is the act of opening the action par-

tially or fully, which disconnects the striker and prevents the

rifle from firing.

Extraction. The means by which the cartridge head is

grasped or levered, thus drawing the case from the chamber.

Ejection. The “kicking out” of the fired case from the receiver,

or removing it by hand as with some single-shots.

All guns, except the blowback actions, operate within the

framework of these eight functions. Various rifles perform one

or more functions simultaneously, and not necessarily in the

sequence listed. In most cases, troubleshooting is a process

of identifying the function wherein a problem occurs, examin-

ing the part(s) that causes the function to occur, and locating

the part(s) that causes the problem.

Troubleshooting

Troubleshooting is probably 25 percent specific knowledge of

the particular rifle you’re working on and 75 percent common

sense. When troubleshooting, look for the four “Ds”—dirt,

dents, dings, and damage. Probably half of the functioning

problems encountered with rifles stem from dirt.

The first step in troubleshooting a rifle brought in with

mechanical problems is to interview your customer. He or

she can save you hours by answering questions concerning

when, how, under what conditions, etc., the problem first

occurred.

These are some questions you can ask your customer. What

is wrong with the gun? When did the problem(s) start? Did

the gun action jam before it started giving the current prob-

lem? Did someone drop the gun before the problem started?

Have there been similar problems before? If so, what was

the remedy? What does the customer think is wrong with

the gun? Ask any additional questions that come to mind as

the result of your initial questions. Look for obvious damage

such as broken, bent, or missing parts, which are quickly

visible to the trained eye.

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To be successful, you must develop an extensive working

knowledge of gun actions and the way they work. Then, it

will be relatively easy to spot the source of most mechanical

troubles.

If a customer interview and quick firearm examination don’t

reveal the problem source(s), it’s time to disassemble the gun

and give it a thorough washing in the degreasing tank.

Caution: Don’t place the wooden stock or other wood parts in

the degreasing tank. I know a supposedly reputable gun-

smith who submerged a Winchester M 94 in the tank. It took

all the varnish off the stock and made the wood very dark. If

it had been my gun, I would have demanded a new stock!

You may discover the problem(s) while disassembling the

gun. If you don’t, go over the gun again, looking closely for

broken, bent, or missing parts, screws, pins, etc. If nothing

is apparent, look for worn parts that may not be functioning

properly. Often trouble arises when a part that looks good

is actually worn to where it no longer reaches far enough to

do its job in the action. This is particularly true of extractors.

While they may look fine, they actually don’t grab the car-

tridge rim due to a weak spring or worn claws.

Extractor Problems

Extractors for many older guns are no longer available. You

can usually repair them by building them up with carbon

steel rod in either a gas torch weld or MIG weld. If using the

MIG, be sure to use the lowest possible heat as it’s all too

easy to overheat and carbonize small parts. (When steel

becomes carbonized, it crystallizes and loses most of its

strength.) After you build the offending part up in the worn

sections, file them to optimum shape, polish, and heat-treat.

It’s necessary to use carbon steel rod for building up extrac-

tors. Case-hardening doesn’t work well for extractors as they

wear through the hardened skin too soon.

Jammed Actions

A “jammed” action is a common problem that brings a cus-

tomer to the gun shop.

Warning: Never trust your customer to know if a gun is

unloaded. He or she may have removed all the cartridges

from the magazine, but one may remain in the chamber.

Your customer may believe he or she fired the cartridge, but

the jam may not have occurred until after a new cartridge

was inserted into the chamber.

Don’t accept a firing pin impression in the primer as absolute

proof the cartridge has been fired. The firing pin may have

hit hard enough to make an impression, but not hard enough

to set off the primer. You must take every precaution to

make sure the cartridge doesn’t accidentally discharge, and

of course, point the muzzle in a safe direction.

Safeties

Safeties made of cheap metal stampings often fail. Although

they seem to be functioning well, a strong trigger pull or

even a sharp jar or bump can bend them just enough to

cause them to fail. This is particularly true of older, lower-

grade .22 rimfire rifle safeties. It seems unconscionable to

me that gun makers would try to save a few pennies on the

metal in something as critical as the safety.

Holes and Pins

Often the problem will be a hole that has worn out of round

where a pin works in it. In such instances you can install a

new part (if one is available) or weld the hole shut and redrill

it. If it’s a larger hole, you can drill it oversize and insert a

bushing.

Warning: Of special importance, and highly dangerous, is

the situation where the firing pin sticks in the protruding

position in the bolt. This can, and frequently has, caused a

rifle to fire from an unlocked action when the shooter shoved

the bolt rapidly forward. In such an occurrence, the bolt will

violently expel from the rear of the gun. This is because only

the weight of the bolt and whatever bolt-retaining system is

in the gun are holding the bolt against the force of the gas

generated by the burning powder.

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The danger in such a situation is proportional to the power

of the cartridge being fired and the type of firearm action. In

a bolt-action where only a bolt retainer holds the bolt in a

gun chambered for .30–06 class, pressures are lethal. The

bolt would drive through one or more persons at high velocity.

Conversely, in a .22 rimfire firing the .22 short cartridge, the

weight of the bolt would largely dampen the force of the tiny

powder charge. A .22 long rifle cartridge will drive the aver-

age bolt hard enough to break the bolt retainer and severely

sting. Also, it could possibly break the fingers holding the

bolt, and the bolt could strike the body hard enough to do

severe damage.

On guns where the back of the receiver is enclosed, the bolt

will be held in the action. Still, in instances of the heaviest

loadings such as the magnum class of cartridges, the extreme

force of the powder gases could rupture the heaviest receiver

and cause severe or lethal damage.

The facts just given should make it abundantly clear that

you should guard against such accidents by always checking

for a firing pin that protrudes from the boltface.

Warning: The speed with which the bolt thrusts forward has

much to do with whether the gun fires if the bolt is closed

with the firing pin stuck in the protruding position. I have

deliberately belabored this point, as it is very dangerous.

Gunsmiths are most likely to come into contact with such

situations and be asked to fix such problems.

Rust

Rust is another major cause of malfunction. The best way to

remove rust is to use Naval Jelly.

Caution: Although Naval Jelly completely removes rust from

metal, it will also remove the bluing. Therefore, you shouldn’t

use Naval Jelly on surfaces that don’t take refinishing.

It’s necessary to wash the jelly from the gun and carefully oil

it after having used this process, as the metal is completely

clean and subject to rapid rusting all over again.

Note: The functions and troubleshooting topics we just dis-

cussed are general and apply to all firearms. Following is a

section that lists essential tools for performing troubleshooting

and repair as well as function and troubleshooting segments

geared to specific rifle action types.

Some Essential Tools

First of all, it’s important to have a good place to work. You

don’t need a fancy gun shop, as you can do most work quite

nicely in your basement. You do need a good workbench and

vise. The old blacksmith’s “Dogleg” or similar vise that has

raised jaws is the best style. It allows more access to the gun

(Figure 32).

A gun cradle is also very necessary for such work as cleaning

and scope mounting. I keep my gun cradle on a desk in my

den (Figure 33) where it’s clean and quiet.

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FIGURE 32—Shown is an old-style gunsmith/blacksmith vise withleather inserts to preventmarring work finishes.

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You should have a place beside the working vise where you

can lay out the tools you’ll likely need for the job at hand.

Figure 34 shows the tools laid out on my bench for a stock

bedding job, which includes changing the stock contour at

the wrist. I use the corncobs as handles on the wood rasps.

They work fine and have been used as file and rasp handles

ever since guns have been made in America.

FIGURE 33—A Gun Cradle.

FIGURE 34—Tools on the Workbench

You should also have a precision tool chest such as the one

shown in Figure 35. It sits atop a metal tool cabinet in my

shop. It holds such tools as micrometers, verniers, depth

gages, scribes, hole gages, telescoping gages, machine

squares, inletting chisels and gouges, and the many other

delicate, precision tools used by the gunsmith.

If at all possible, it’s good to have a place to sight in and test

the customer’s guns. You’ll need to make some arrangement

to shoot when testing guns, sighting in, and working up loads

for the customer’s guns. I’m fortunate enough to have a few

acres along the bank of the Potomac where there’s a 300 yard

range available near one of my workbenches. It’s also nice

(but not required) to have a chronograph available to help in

determining the most efficient and accurate load when hand-

loading for custom work (Figure 36).

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FIGURE 35—The GerstnerMachinists Chest consists ofwood, so fine precision toolswon’t sweat as they do inmetal chests.

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Lever-actions: Function andTroubleshooting

Modern lever-actions are direct descendants of the Volcanic

rifle, introduced in 1855.The first Volcanic rifle

carried its powder charge in the base of a coni-

cal, hollowed-out bullet. A cardboard or cork

disc kept the powder and primer in place.

Because the “cartridge” had no gas seal, pow-

der and velocity were low and the rifle passed

into oblivion in 1857 (Figure 37).

FIGURE 36—Shown is a shooting bench in one of Mr. Wood’s shops with a rifle resting on sandbags, a spottingscope, and an Oehler M 35P chronograph for testing velocity.

FIGURE 37—These drawings show theVolcanic rifle (top) with its oddball car-tridge, and its successor, the Henry,which fired the world’s first metalliccartridge.

One of the Volcanic Company stockholders, a fellow named

Oliver Winchester, purchased the company’s patents. His

foreman, Tyler Henry, redesigned the Volcanic and created a

surprisingly modern-looking rifle that fired the first metallic

cartridge—a .44 caliber rimfire, also designed by Henry. (The

“H” on the head of Winchester rimfire cartridges is in honor

of Henry.) The .44 caliber rimfire rifle, known as the Henry

Repeater, played a major role in the winning of the West.

The basic Henry model evolved into a series of famous

Winchester lever-actions:

• The Model 66, chambered for the .44 Henry cartridge

• The Model 73, chambered for the .44/40 centerfire

• The Model 75, chambered for more powerful black

powder centerfires, such as the .45/75.

The year 1881 introduced the first Marlin lever-action. It was

chambered for the .45/70/405 government cartridge. Later,

John Moses Browning designed improved lever-actions, later

sold to Winchester. They introduced the lever-actions as the

Winchester Model 1885 (the first smokeless cartridge, the .33

WIN.); the Model 1894, which introduced the famous .30/30

cartridge (Figure 38); and the Model 1895.The latter differed

from its predecessors in that it incorporated a box-type

rather than a tubular magazine, and was perhaps the first

lever-action that could safely use pointed spitzer-type bullets.

The 1895 was the favorite rifle of Theodore Roosevelt and

was chambered for such powerful cartridges as the .30–06

and .405 WIN. The company discontinued it in 1931.

Other early manufacturers of U.S. lever-actions were

Spencer, Marlin, and Savage. Of these, the Winchester 94,

Savage 99, and the Marlin, in its original form plus a new

short-action design, are still in production and chambered

for centerfire cartridges.

Most lever-actions utilize a tubular magazine feeding either

through the buttstock for .22 rimfire rounds or from a tube

mounted under the barrel for centerfire cartridges. Others,

using relatively powerful centerfire cartridges, employ a box-

type magazine. These include the Winchester 88, Sako

Finnwolf, and Savage 99.

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The Sequence of the Eight Functions inPopular Lever-action Rifles

The Winchester 94, Marlin 336, and the Savage 99 are the

most popular centerfire, lever-action rifles in use today. In

this section, we’ll relate the eight functions of rifle actions to

the operation of the Winchester 94, the Marlin 336, and the

Savage 99.

Winchester 94 and Marlin 336

First, let’s discuss the Winchester 94 and the Marlin 336. In

these rifles, the rifle (1) UNLOCKS as the lever is pushed

down. If a cartridge is in the chamber, it’s (2) EXTRACTED,

and (3) EJECTED. While the breech bolt moves backward, it

simultaneously cams the hammer back and down until the

hammer sears engage the trigger, thus (4) COCKING the rifle

on the opening of the action. Also, as the lever moves down,

FIGURE 38—This is the famous Winchester Model 1894. The cutaway view shows the rifle loaded.

a cartridge moves from the tubular magazine by spring com-

pression onto the lifter or “carrier” platform, aligning it with

the chamber (5) FEEDING.

When the lever is raised, the bolt moves forward, strips the

cartridge off the lifter, and carries it up into the chamber,

thus accomplishing (6) CHAMBERING. After the lever is fully

raised and flushed with the receiver, the action is (7) LOCKED

and the trigger can be pulled, thus (8) FIRING the rifle.

Figures 39–41 depict the inner workings of a modern lever-

action, the Marlin Model 336.

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FIGURE 39—With the rifle loaded and cocked,pulling the trigger releases the upper part of the trig-ger from the notch in the hammer. The hammer thenmoves forward and strikes the firing pin, detonatingthe cartridge. (Drawing courtesy of Complete Book of

Rifles and Shotguns by Jack O’Connor)

FIGURE 40—When the lever is pushed forward, thelocking bolt moves downward, disengaging from thebolt. The tip engages a slot in the bolt and movesthe bolt to the rear. As the bolt moves backward, anextractor hook pulls the fired case out from thechamber to a point where the spring-loaded ejectorkicks out the case. At the same time, the magazinespring forces a cartridge onto the carrier. The levercompletes its outward arc and the carrier and car-tridge start moving up. (Drawing courtesy of

Complete Book of Rifles and Shotguns by Jack

O’Connor)

FIGURE 41—As the lever returns to its original posi-tion, it first engages a pin on the carrier rocker,which cams the carrier into loading position. As thelever continues moving toward “close,” its tip pushesinto the bolt slot, moving the bolt forward and cham-bering the cartridge. When the lever fully returns, thelocking bolt rises to match the notch in the bolt, thusaligning the safety firing pin (see first drawing). Therifle can now be fired. (Drawing courtesy of Complete

Book of Rifles and Shotguns by Jack O’Connor)

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The Savage 99

In the Savage 99, the operation sequence of the eight func-

tions varies only because the Savage is cocked on the closing

of the action, while the Winchester and Marlin cock on opening

(Figures 42 and 43).

FIGURE 42—The Savage Model 99, Modern Version (Photo supplied by Reinhart Fajen, Inc.)

FIGURE 43—Shown is the cutaway view of the original Savage Model 1899. The top view shows the lever in theforward position and the bottom view with the lever closed. The design of contemporary Model 99s is essentiallythe same.

How Lever-actions Lock Up

The Winchester and Marlin rifles utilize a vertical rising block

arrangement for lockup. As the breech closes, the locking

block rises up to lock the bolt at the rear.

In the Savage 99, the shoulder at the rear of

the breech block wedges up against a corre-

sponding shoulder at the top rear of the action

when the lever closes (Figure 44). The breech

block also bears snugly against the sides of the

receiver. When the fit is perfect, as is usually

the case in newer 99s, the result is an enor-

mously strong action.

Most of the cheaper .22 caliber rimfire lever-actions lock up

by simple overbalanced camming. Closing the lever exerts

sufficient force against the cartridge head to achieve a satis-

factory seal. Chamber pressures are so low that not much

locking strength is needed.

Drawbacks of Lever-actions

Inadequate lock-up surface and inadequate strength are

characteristics of the older lever-action designs and even of

the newer configurations, such as the current Winchester 94

and Marlin 336 compared to most modern bolt-actions.

The older lever-actions with tubular magazines are limited to

flat-nosed bullets because of the danger of recoil causing the

point of one bullet to explode the primer of the next cartridge

in line. As most lever-actions lock up at the rear, cases have

a habit of stretching, making frequent trimming a must for

the reloader.

Troubleshooting Lever-actions

Dented Tubes

Lever-actions almost always have the magazine in a tube

located under the barrel. This tube often gets dented to the

point where the follower can’t push past the dent. The fix is

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FIGURE 44—When the lever is closed on aSavage Model 99, the breech block rises andwedges into position against the shoulder insidethe receiver.

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to drive a rod with a slight radius on the leading edge (which

is just under the inside tube diameter) down the tube to

push out the dent. Clean the tube thoroughly with a wire

brush to remove all rust and dirt. Then, turn a short section

of rod to a diameter about .001 under the I.D. of the tube

and push it to the dent and tap the dent against the rod with

a hammer until the dent disappears. Finally, grease the mag-

azine tube inside with a rust preventive before assembling

the spring and follower in the tube (Figure 45).

FIGURE 45—Exploded View of a Lever-action Rifle

Headspace Problems

Another common problem with lever guns is headspace. As

lever guns lock up at the rear of the action, there’s a great

tendency for the sides of the action to stretch. This is espe-

cially so when the shooter uses heavy loads. Although such

loads are within the pressure capacity of the action as indi-

vidual rounds, they tend to gradually lengthen the action

over extended periods of use.

Sometimes there’s excessive headspace in Winchesters that

lock up by lugs running inside mortises cut into the side

walls of the action. You can correct this by MIG welding a

ridge of metal up the sides of the lug where it bears upon

the mortise. Then, mill the welds down to the proper thick-

ness to correct the headspace problem.

Note: If you don’t have a milling machine, you can use a drill

press with a compound vise as a milling machine. Or, you

can smooth up the added metal by rough grinding on a

bench grinder and finish grinding with a small grinding

wheel set into the chuck of your drill press.

Place two guide fingers on the original surface between the

built-up sections to keep the part aligned while being ground.

Also, set a guide bar to hold the alignment from the back

surface of the lug. Whatever method you use, it’s necessary

to use a dial indicator to ensure there’s no taper in the lug.

It’s also necessary to measure the ground surface of the lug to

maintain the proper headspace. You must have established

just how much to move the bolt forward to correct the head-

space problem before starting the operation.

I’ve heard of adding a heavy chrome plating to the lug to

correct headspace. I’ve not tried this, but I pass it along for

consideration on the older guns where no replacement parts

are available. Always be sure you’re safety conscious in your

repairs.

Cracked Side Walls

On a lever-action, the side walls are the restraining force for

the pressures generated when firing.

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Warning: Always check the side walls of the action on guns

that have developed excessive headspace for cracks. The steel

used in most lever-action rifles is soft enough that it will

usually stretch considerably before cracking. On some rare

occasions, both Winchester and Marlin lever-action rifles are

said to have developed cracks in the side walls. I have never

personally found such a gun, but I did see a wrecked M 94

that let go on the left side of the action. A part of the surface

where the side wall separated rusted in a way that indicated

it had cracked long enough to rust before it let go. The shooter

didn’t sustain serious injuries. Fortunately, he was a left-

handed shooter, and the explosive force went away from him.

Had the shooter been firing the rifle from his right shoulder,

it’s quite likely he would have sustained serious injuries, if

not been killed, by the breech bolt, which no one ever found.

It’s a good idea to magnaflux any lever-action that has devel-

oped excessive headspace to check for hidden flaws within

the side walls. We’ll describe magnafluxing in detail later in

the course.

Some years ago, Savage brought out a bolt-action rifle cham-

bered for the .30-30 WIN. cartridge. This bolt-action rifle was

stronger than the lever-actions, and there were cartridges

made up especially for the bolt-action Savages in order to get

additional power from these rifles. While these “hot loads”

were clearly marked for bolt-action rifles, sometimes they got

mixed in with regular .30-30 loads and found their way into

lever-action rifles, which weren’t intended to withstand the

higher pressures. I don’t know of these loads blowing an

action, but there were quite a few actions around that sud-

denly developed excessive headspace at the time.

I also remember some customers who dropped by to ask if it

was possible to reload cartridges to the bolt-action Savage

pressures and use them in their Marlin and Winchester lever

guns. I believe the Marlin M 336 to be quite a bit stronger

than the older, square-bolt guns. It might be safe to make up

loads with a few more grains of powder using 150 grain flat-

point bullets for a flatter shooting load in the 336. However, I

would never recommend this to anyone or tell them it’s a safe

practice. In fact, I recommended against this hot loading, but

two of these same persons later ended up with headspace

problems in their lever-action .30-30s. I guess it’s pretty hard

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for some to admit they used cartridges not intended for their

guns, and which they were warned about using to get more

power. I have taken the time and space to tell this story to

point out that you should never trust people to follow your

recommendations even when they ask for and seemingly

respect your opinion.

The gunsmith is a respected authority, so you must be very

careful in what you say. Folks will feel you’re being conserva-

tive and think they’re allowing for your overcautious answers

in doing as they wish. They might try to use your advice,

even though you recommend against their plans, to justify

their acts.

Sometimes it can be downright scary, as in the following

example about a Remington M 788 in .30-30. This is a strong

action that can be loaded to .30-06 pressures; the action is

too short to accommodate the .30-06 cartridge. However, it’s

chambered in calibers that generate .30-06 pressures and in

this action, the .30-30, with judicious selection of powders,

can be safely loaded to .300 Savage velocities. Shortly after

the idea that the .30-30 could be loaded to 2,500 fps for use

in the Rem. M 788, one of my neighbors stopped by and

asked if it would be all right to load the Hodgdon BL-C (2)

loading. Such a loading gave 2,500 fps with a 150 grain

bullet in the Rem. M 788, in his Savage .30-30 rifle. He

reminded me that I had told his buddy that the Savage was

a lot stronger than the Marlin lever gun when his buddy

asked if it was safe to load the 2,300 fps Savage load in the

Marlin. Since his buddy had gotten by with using the hotter

load against my recommendation in the Marlin M 336, it

surely must be safe to use the .300 Savage class load in his

Savage .30-30.

Now get this: I told him that I had plainly told his buddy that

it was unsafe to load the Savage load for use in the Marlin.

His answer was, “Yeah, but you didn’t scream when he men-

tioned the loading, and we sorta figure if it’s really dangerous

you’ll scream when you hear the load.” This should illustrate

how careful you need to be when dealing with untrained

shooters. (Actually, previous to this incident, I had consid-

ered the neighbor to be a fairly accomplished and competent

reloader.) I will never make that mistake again. So this time I

screamed! I emphatically told him that the M 788 .30-30 load

82

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used in his Savage bolt-action would in all probability blow

his head off. I haven’t heard of this customer being seriously

injured, so I assume he took my warning.

Faulty Ammunition

Failure to fire can stem from faulty ammunition. This is

common with reloads in which the primer has been set a

bit too deep into the case.

Firing Pins and Springs

A very frequent cause of failure to fire in any type action is a

weakened hammer or firing pin spring. You can easily solve

this by installing a new spring.

Another common problem with Winchesters is firing pin wear

in which the firing pin is both shortened by wear and by the

hammer end being peened shorter from years of firing. Dirt

and crud in the firing pin assembly, and sometimes ahead

of the hammer, can slow the fall of the hammer so it doesn’t

strike the primer hard enough to fire.

An older Winchester or Marlin lever-action has more value as

a collector’s item than as a hunting arm, if it has mechanical

problems. Such guns can sell “as is” for more than the cost

of a new hunting rifle if rebarreling or rebluing hasn’t ruined

them. If you need a hunting rifle, a wise idea is to sell the

old-timer and buy a new modern hunting rifle with a part of

the proceeds. If the oldie is a keepsake or heirloom, don’t try

to have it repaired in any way that will modify it and lower

its value as a collector item. Just retire it to a place of honor

on the wall and use a newer, less valuable, gun for hunting.

We included the previous information in the lever-action section

since a large number of the deer rifles in use are collector

items. The information regarding older rifles is equally appli-

cable to other type actions that have become valuable.

Oversize Firing Hole

A problem common to many types of older rifles is an over-

size firing hole in the bolt face. This often causes difficulty in

extraction due to the primer being forced back into the bolt

face. It also allows the unsupported primer to rupture and

hit the shooter in the face with a blast of hot gas, which can

be extremely hazardous to the eyes. There are two common

solutions to this problem. One is to weld the firing pin hole

shut and redrill the hole to the proper size. I don’t particularly

like this method, as it requires heat-treating the bolt again,

and repeated heating of carbon steel weakens it. The method

I prefer is to drill the bolt face and tap a 5/16 inch thread into

it. Then, insert a section of heat-treated Allen screw into it

and clean the ends up so they’re flush with the bolt surfaces.

After you insert the threaded piece, drill it to the proper size,

and smooth it up, “stake” it with a punch on the inside sur-

face so it can’t move in the threads. This will hold it perma-

nently in place, but in the event that it becomes worn in the

future, it is easy to remove the plug and insert and redrill

another one.

Final Thoughts on Lever-actions

Unusually superior rifles stand out from others of their kind.

The first repeating rifles were lever-actions, and they’ve

earned their place in the firearms hall of fame. My candidate

for the outstanding lever-action rifle is of much more recent

date. It’s the Marlin .444S rifle, chambered for the .444

Marlin Cartridge, which gives the shooter who needs a short,

reasonably light and fast-handling rifle a lot of knockdown

power for hunting critters in the woods (Figure 46).

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FIGURE 46—The .444 Marlin rifle with Leupold Vari-X III 1.5 � 5 scope is a fine brush gun for most any NorthAmerican game at moderate ranges.

Rifles 85

The Savage M 99 is a close second candidate for honors in

the lever-action class. It’s an excellent rifle with sufficient

power. The Marlin lever-action rifle currently being made in

caliber .45-70 is also a splendid woods rifle, but it has

caused cartridges to be made that, if fired in the Springfield

Trapdoor rifles, would ruin the rifles. As with the hot .30-30

loads, I discourage such loadings for the very real danger

they present to the unknowing and the fool.

The Winchester M71 is a real powerhouse among lever-

actions. If we rated lever-actions solely on power, it would

be the hands-down favorite, chambered for the .348 Win.

Cartridge. The M71 is too heavy for most folks to carry

easily or comfortably.

The Savage 99 is an internal hammer gun with a rotary mag-

azine that’s an excellent design. It usually feeds flawlessly,

but is subject to problems if dirt gets into it. The most com-

mon dirt is pieces of twig that find their way into the action

if it’s cycled while standing in brush. The lockup is different

from most lever-actions because it locks by camming a

“hump” into the back of the breech recess. This is a very

strong lockup. The only trouble I know of with these is that if

the shooter shoots hot loads, the action may sometimes be

difficult to open. If this occurs, strike the top of the breech

block sharply with a wooden mallet. If you’re in the woods,

use a length of wood to tap the block down until free. Never

try to force it open by pulling harder on the lever; you’ll only

succeed in disengaging the lever from the breech block.

The Winchester M 88 and the Browning BLR rifles use a

lever to operate the action. But the lockup is like the multilug

bolt actions and should be treated in the manner described

under bolt-action troubleshooting.

The Marlin M 39 and 39-A are two longtime favorites among

.22 centerfires, and recently the Winchester M9422 has

taken its place among lever-action favorites. Troubleshooting

these models is as with other lever-action rifles.

It’s necessary to mention the Winchester M 250. This ham-

merless lever-action .22 rimfire has what seems to me to be

very poor construction, due to a locking mechanism that’s

similar in principle to the Model 12 shotgun. If it were as

tough and durable as the Model 12, it would be a dandy.

However, the locking plate, which cams into the locking

recess, seems to peen the softer receiver metal away until it

develops excessive headspace. The fix is to install a hardened

pin or weld with a hard alloy rod behind the shoulder to

maintain the locking position. This rifle has other problems

in a number of parts that are too lightly constructed of sheet

metal, and in its cam pin, which is riveted into the locking

plate arm and wears loose with continued use. There’s no good

fix except replacement of the entire locking plate assembly.

Lever-action rifles, with the notable exceptions of the Savage

M 99 and the Winchester M 88, are of only moderate accura-

cy. (I frankly don’t know how well the Browning BLR shoots

as I have never tested one.) Recently, makers of lever-actions

have changed the attachment of the magazine tubes to the

barrel and eliminated the main cause of their poor accuracy.

You can greatly improve the accuracy for some Winchester

M 94 rifles by adjusting the attachment of the forearm and

magazine tube. There’s no ironclad rule as to whether to

loosen or tighten them. Try both loosening and tightening

them to increase accuracy. Sometimes inserting a section of

Popsicle stick on each side of the forearm will result in greatly

improved accuracy. In other instances, exactly the same

treatment of another rifle will show no result whatsoever or

actually decrease accuracy.

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Self-Check 6

Indicate whether the following statements are True or False.

_____ 1. You should always check the side walls of the action for cracks on guns that havedeveloped excessive headspace.

_____ 2. Modern lever-actions are direct descendants of the Volcanic rifle introduced in 1855.

_____ 3. In older lever-actions with tubular magazines, you should use flat-nosed bullets.

_____ 4. The Winchester M 88 and Browning BLR are lever-actions that house the same locking mechanism as other lever guns.

_____ 5. In magazine-fed rifles, one of the first things to check in feeding problems is dentsin the magazine.

Check your answers with those on page 130.

PUMP-ACTIONS: FUNCTION ANDTROUBLESHOOTING

The Sequence of the Eight Functions in Pump-action (Slide-action) Rifles

In the previous section, we discussed the sequence of the

eight functions in lever-action rifles. In this section, we’ll dis-

cuss the eight functions in pump-action rifles. You move the

bolt or breech block in such rifles forward or back by manip-

ulating the forearm. The forearm is attached to the bolt

assembly by one or two action bars, depending on the

firearm (Figure 47).

The sequence in the Remington Model 760, and most pumps,

follows.

As the forearm is pulled to the rear (after firing or manual

release of the action lock), it (1) UNLOCKS the action, then

(2) EXTRACTS, and at the end of the movement (3) EJECTS

the cartridge. As the rearward bolt travel stops, the hammer

is (4) COCKED. At this point the magazine has accomplished

(5) FEEDING by lifting the cartridge into the uppermost posi-

tion. When the forearm moves forward, the bolt strips the

cartridge from the magazine and pushes it into the chamber,

thus accomplishing (6) CHAMBERING. In the final forward

motion, the bolt rotates and the lugs are engaged, thus

accomplishing (7) LOCKING. The rifle is now ready for (8)

FIRING. Figures 48–50 illustrate the sequence.

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FIGURE 47—The Remington 760 “Gamemaster” and its newer versions are the only slide-action rifles to handlesuch high-intensity cartridges as the .30/06, .270, .308., etc.

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FIGURE 48—As the forearm moves to the rear, the action bar and bolt assembly are pushed backward, simultane-ously pressing the hammer downward and ejecting the fired case. A “loop” spring with a claw in the face of thebolt (see small left-hand drawing) hooks under the rim of the cartridge and extracts it from the chamber. Whenthe case clears the chamber, the ejector spring in the bolt flips the case clear. The magazine spring then pushes anew cartridge upward. (Drawing courtesy of Complete Book of Rifles and Shotguns by Jack O’Connor)

FIGURE 49—When the forearm is pushed forward, the action bar and bolt assembly move forward, stripping thecartridge from the magazine and into the chamber. The notch in the sear retains the hammer in the cocked posi-tion. As the bolt continues moving forward, the bolt threads contact the locking lugs (see small illustration). Acam on the carrier engages a curved slot in the bolt, causing the bolt to turn and thread into the locking lugs.(Drawing courtesy of Complete Book of Rifles and Shotguns by Jack O’Connor)

How Pump-actions Lock Up

The Remington 760, essentially a Mauser turning-bolt

design, has a multiple-lug lockup. As the bolt is seated, it

turns, locking the lugs in the barrel extension. Other pump-

actions lock up in a variety of different ways. The old

Remington 14 and 141 employed a single lug lockup similar

to the Krag-Jorgenson, which, because of the one-side sup-

port, limited the action to pressures of not higher than

42,000 psi (.30-30 class).

Troubleshooting Pump-actions

The pump-action rifle is an offshoot of the popular pump

shotguns (Figure 51). Shooters who regularly used and liked

the pump shotgun wanted a rifle that handled and func-

tioned like the shotgun they were familiar with for their deer

hunting. The first really “serious” centerfire pump rifle was

the Remington Model 141 chambered for the .30 Remington,

.32 Remington, and .35 Remington cartridges. The .35

Remington was by far the most popular. The M141 had a

spiral magazine under the barrel that prevented the points

of the pointed bullets from bearing on the primer of the

round ahead of it. This major improvement allowed the

use of bullets of better ballistic coefficient.

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FIGURE 50—Pulling the trigger causes the trigger sear to disengage from the notch on the hammer, permittingthe mainspring to drive the firing pin against the cartridge primer. (In the interest of clarity, we don’t show thesafety lock and disconnector in this illustration.) (Drawing courtesy of Complete Book of Rifles and Shotguns by

Jack O’Connor)

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As mentioned, the Remington M 760 and the Savage M 30

arrived on the scene to adequately fill the needs of pump rifle

devotees. The Remington 760 is a rotary bolt design that’s

capable of withstanding heavy chamberings of .270 WIN. and

.30-06 calibers. Like the Winchester M 88 lever-action rifle,

you should service the Remington 760 using the instructions

for bolt-actions.

FIGURE 51—Exploded View of a Pump-action Rifle

Magazine Cutoff Problems

The most frequent problem with pump rifles is the tubular

magazine cutoff’s failure to catch the second cartridge after

the lifter picks up the first one. An equally frequent problem

is its failure to release a cartridge to the lifter. Both malfunc-

tions are almost invariably traceable to our old villains: accu-

mulated dirt and crud. It always seemed that pump guns

were the most vulnerable of all action types to the ravages of

crud.

Annual Cleaning Required

The owner of a pump gun should do an annual action

cleanup using a pressurized degreaser/cleaner such as Gun

Scrubber. To clean a pump action, insert the extension spout

into the action and move it about while spraying the solvent.

Allow the solvent to soften the accumulated crud a few min-

utes, and again wash the action out with the spray. This

should eliminate about 95 percent of the problems you would

have encountered with pump-action rifles.

.22 Rimfire Pump Rifles

In addition to the centerfire pump-action rifles just listed,

there are many .22 rimfire pump rifles. Perhaps the best of

them are the Winchester Model 62 hammer model and its

cousin, the model 61 hammerless pump.

The Remington hammerless models 241 and 121 are also

excellent rifles. Of more recent production is the Rossi gallery

rifle, which seems to be an exact copy of the Winchester

model 62 hammer gun. These are all excellent guns, but my

favorite and candidate for all-time great .22 RF pump rifle is

the long-obsolete Winchester model 61 hammerless rifle. It’s

capable of excellent accuracy, far above the level of accuracy

demonstrated by the other guns mentioned. I have a model

61 that gives 3/4 inch 50 yard groups. I got it back in the late

1940s mounted with a Weaver J4 scope, which was then

state of the art. It was deadly squirrel medicine. This model

gets my vote for the all-time outstanding .22 RF pump gun.

The M 62 is a close second (Figure 52).

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Problems Associated with Takedown Models

In addition to the usual problems brought on by accumulated

crud, the aforementioned Winchester rifles suffer from being

takedown models. They can separate at the action, one side

remaining on the stock section and the other side of the

action staying with the barrel and magazine. The separation

leaves the entire working parts section of the action exposed

to rough handling and even more dirt. Then, damage occurs

if the sections aren’t put together properly. They also tend to

work loose at the takedown joints.

Dented Tubes

The information on dents and dings and on cleaning and

greasing the inside of tubular magazines, given in the lever

gun section, is also applicable to pump-action rifles because

they’re tubular magazine rifles. Sometimes the Remingtons

would have a bit of trouble with the shell lifter getting stuck

or not starting the cartridge into the chamber properly.

All in all, there are very few problems with any specific pump

rifles of which I’m aware that would require special notice.

So, the general rules of rifle troubleshooting presented earlier

apply.

Bolt-action Rifles: Function andTroubleshooting

Probably the first true turn-bolt rifle was the Needle gun

developed by Dreyse in the late 1830s. It didn’t shoot nee-

dles, but was so named because of its long, needlelike firing

pin that protruded from the rear of the bolt when cocked.

FIGURE 52—The Winchester model 62 hammer model, one of the first pump .22 rifles, is a collector’s item today.

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The rifle’s paper cartridges and leaky ignition system were a

drawback. Shooters preferred to fire from the hip and thus

escape the blowback and black face that could do as much

damage as the business end of the arm.

The first really successful bolt-action design was the 11mm

Mauser single-shot of 1871, which employed a true turning-

bolt design (Figure 53). In 1884, it was equipped with an

under-barrel tubular magazine, holding eight .43-caliber

Mauser cartridges.

The next important step in the evolution of the bolt-action

was the Spanish 1893 Mauser. It was developed about the

same time as the Krag Jorgenson rifle of Norway, which the

U.S. military adopted in 1892.The Mauser used a staggered

column clip magazine as opposed to the Krag’s ungainly box

magazine, which had to be loaded with single cartridges. The

Krag had only one locking lug while the Mauser had two,

thus providing superior strength.

The Model 1893 Mauser was the forerunner of the greatest

individual firearm design of all time: the Model 98 (Figure 54).

This model incorporated the two front-locking lugs of the 93,

but added an additional locking lug toward the rear of the

action for extra strength. Also, the cocking piece was shrouded

to protect the shooter from escaping gas.

94

FIGURE 53—Shown are cutaway views of the Mauser 11mm with the under-the-barrel tubular magazine added in 1884.

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The only other early turn-bolt rifle of any consequence was

the Mannlicher, developed in Austria, which incorporated a

spool-type magazine similar to that later used in the Savage

95 and Model 99. The bolt handle was positioned ahead of

the receiver bridge, necessitating a split bridge, which, when

scopes were later developed, made mounting them difficult.

How the Eight Basic Functions Apply inModern Bolt-action Rifles

For purposes of discussion, we’ll consider the Model 700

Remington and assume that the rifle has just been fired.

Refer to Figures 55 through 59 as we discuss the functions.

FIGURE 54—The Swedish M40 Variation of the 1898 Mauser, Caliber 8 �� 63mm

FIGURE 55—Model 700 Remington (Drawing courtesy of Complete Book of Rifles and Shotguns by Jack O’Connor)

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FIGURE 57—Japanese service rifle (Arisaka). The illustration shows details of a mechanism with the rifle cockedand ready to fire. Note the position of the trigger sears and the unique mainspring—positioned inside the hollowfiring pin section.

FIGURE 58—The Italian Carcano 6.5mm carbine is identical to the rifle except that the barrel is 21 inches long,10 inches shorter than on the rifle.

FIGURE 59—Shown is the Carcano cutaway view illustrating the action open and with loaded clip magazine. Thisfirearm cocks on closing like the early Mausers.

FIGURE 56—6.5mm Japanese Arisaka, Model 38

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1. As the bolt handle is raised, the bolt lugs rotate and

(1) UNLOCKING takes place. A notch at the bottom of

the bolt handle engages simultaneously and raises a

spur on the firing pin head, thus pushing the firing pin

to the rear and compressing the mainspring.

2. When the bolt assembly is drawn back, (2) EXTRACTION

occurs as the case is drawn from the chamber. A circular

spring in the face of the bolt tightens the claw, gripping

the case head tightly. When the fired case clears the

chamber, the spring-loaded ejector (3) EJECTS the spent

cartridge. The magazine spring forces the next cartridge

up into loading position (4) FEEDING.

3. As the bolt moves forward, it strips the cartridge from

the magazine, (5) CHAMBERING it. When the bolt

thrusts fully forward and turns down, the lugs engage

the chamber recesses, accomplishing (6) LOCKING. At

the same time, the sear engages the firing pin head,

(7) COCKING the rifle.

4. When a shooter squeezes the trigger, it disengages the

sear from the notch on the firing pin head. The main-

spring thrusts the firing pin forward, (8) FIRING the

cartridge.

Lock-up Systems, Bolt-action Rifles

Bolt-actions lock up by means of lugs on the bolt face, which

when rotated by the action of the bolt handle, engage recesses

in the chamber (Figure 60). The Krag had one locking lug;

the 93 and 98 Mausers have two locking lugs. The Krag was

designed to contain pressures up to about 40,000 psi, the 98

for about the same pressure level. However, if the steel is of

the proper hardness, good 98 actions can easily accommo-

date pressures up to 55,000 psi—the maximum safe limit for

today’s magnum cartridges.

Multiple Locking Systems

As cartridges became more powerful, the need for a stronger

system became paramount. The solution was obviously a

system that employed multiple locking lugs. This adds to

the amount of bolt-to-chamber locking or shearing area and,

theoretically at least, increases strength. We say theoretically

because, if all lug surfaces don’t bear fully and equally, the

action weakens and accuracy suffers. You can check the lug

surfaces by applying Prussian blue to the lug areas and then

checking the receiver recesses for color.

At least one modern bolt-action of super-magnum persuasion

employs the front-locking multiple-lug principle—the

Weatherby Mark V, with nine small lugs (Figure 61). The

Remington 788 and Schultz & Larsen Finnish rifle, both

obsolete, used a rear-locking, multiple-lug setup.

In the Weatherby, the lugs are the same diameter as the bolt

and the bolt is the same size as the inside of the receiver.

The cartridge head is fully enclosed and

the action is slick and smooth.

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FIGURE 60—Shown are three types of bolt-actionlock-up systems. The top drawing illustrates the con-ventional Mauser two-lug lock-up, with the lugs onthe bolt engaging recesses in the receiver ring. Themiddle drawing shows the single-lug lock-up used onthe Krag-Jorgenson, some early side-actions, andother rifles. Support at one side only often changesbullet impact drastically when cartridges differentfrom those used in zeroing are fired. The bottomdrawing illustrates the multiple lugs, which serve as“threads.” When all lugs bear evenly, the action isstronger than the two-lug design.

FIGURE 61—Pictured is a close-up of theWeatherby Mark V action showing multiplesmall lugs and recesses in the receiver.

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The multiple-lug design (or interrupted thread design), while

primarily found on newer rifles, actually goes back to an

earlier period. The system was probably first introduced

by Charles Newton, a turn-of-the-century firearms and

cartridge designer, in the rifles he made for his then- and

still-impressive Newton cartridges. Not only was the multiple-

lug concept exceedingly expensive from a production stand-

point, but the design in Newton rifles was an entire disaster.

A shooter could fire the rifle without locking the bolt. The

maiming of a number of shooters by bolts flying backward

caused the discontinuation of the arm.

Other early rifles, notably the Remington pump and some

autoloaders, used multiple lugs. Today rifles of lever, pump,

and auto-loading design use the system.

An advantage of the multiple-lug design in bolt-actions is

short bolt lift. The standard Mauser action requires a 90

degree lift to open the action. Adding additional lugs at

the front or rear of the bolt shortens the bolt lift to 45-60

degrees. This provides faster repeat shots and ample clear-

ance between the bolt handle and the scope bell.

Gas Venting, Bolt-action Rifles

Since the invention of the self-contained cartridge, the need

has existed to provide the shooter with protection against

escaping gases usually caused by leaky primers or failure

(rupturing) of the brass cartridge. Such escaping gas or

blowback, if not diverted, could travel down the length of

the firing pin and directly into the eye of the shooter.

Therefore, gas ports are always engineered into the

modern rifle (Figure 62).

FIGURE 62—Shown are gas escape ports. Early Springfields(1) had only one gas port; later models incorporated a second port, similar to the Enfield (2). Excess gas is thenexhausted through the ports. The Mauser 98 left little roomfor improvement. Two gas ports, oblong shaped, appear onthe left side of the bolt and extend into the firing pin hole.While most escaping gases exit through these apertures,any gases traveling along the outside of the bolt woulddivert to the side by the shieldlike design of the forward bolt sleeve.

Such relatively high-pressure actions as the Weatherby utilize

a number of gas ports along the side of the bolt (Figure 63).

Safeties on Bolt-action Rifles

There are generally three types of safeties employed:

1. Those that disconnect the striker as in the Weatherbys

2. Those that lock the striker, as in the original and

commercial Mausers

3. Those that merely lock the trigger and prevent its

being pulled.

Manufacturing Bolt-action Rifles

The receivers in older rifles were usually forged from solid

steel billets. Current production methods incorporate invest-

ment castings in which the metal is formed to tolerances that

eliminate practically all machining and millwork. The process

is cheaper and the molecular structure of the steel is such that

investment castings are much stronger than those forged

from metal blocks. No internal stress is set up within the

receiver, such as that caused by forging and metalworking.

Today there are basically three different lengths of bolt-action

designs—short, medium, and “standard”—plus the compara-

tively new magnum-length action (Figure 64).

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FIGURE 63—Notice theWeatherby Mark V,showing triple gas portsin the side of the bolt.

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Troubleshooting Bolt-action Rifles

The bolt-action is the most trouble free of all the actions,

with the possible exception of the falling block single-action.

Still, problems occur regularly with even the bolt-action.

First, of course, is our old friend, “accumulated crud.” In

the bolt-action, crud isn’t as serious as in other action types,

due to the greater camming action of the bolt and absence

of many small weak parts in the relatively simple bolt-action

(Figure 65).

FIGURE 64—Sako is but one ofmany manufacturers who makeessentially the same action indifferent lengths for specificlength cartridges. In addition to the three actions shown, Sako also makes a long magnum version.

Stuck Cases

Stuck cases are probably second in troubles with the bolt-

action, due in part to the higher pressures generated by

bolt-action loads and the fact that many bolt-action fans

reload. Reloaded cases tend to stick for several reasons. Chief

among them is that reloaded ammunition is generally loaded

to higher pressures than factory ammo. For example, if it

were not for the low number of cast-action Springfield rifles

chambered for the .30-06, the .30-06 factory loadings would

shoot a lot flatter. Also, the .270 WIN. would show little, if

any, advantage in trajectory over the .30-06. Hot loads tend

to make cases wear out much faster and to separate, leaving

part of the case in the chamber.

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FIGURE 65—Exploded View of a Bolt-action Rifle

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Note: You might not be familiar with all of the bolt-action

rifles that come into your shop. But don’t worry—I would

question the veracity of anyone who claimed to be familiar

with all of the bolt-actions available today. One has only to

look through the pages of the Shotgun News or a similar

publication to realize there are new bolt-actions appearing

every day. It’s truly impossible for the gunsmith or anyone

else to be familiar with all of the rifles available today. The

best you can hope for is to be familiar with the sporting rifles

available and the more common military conversions that are

most likely to appear at your shop.

As already mentioned, the bolt-action locks by turning lugs

into recesses cut into the action. There may be one or more

lugs extending to the front side of the bolt as in the Mauser

and similar actions such as the Springfield, Winchester M

70, Remington M 700, and many others. The lug can be

an interrupted screw thread at the front of the bolt or an

interrupted screw thread at the rear of the bolt as in the

Remington M 788. The lug can also be several medium-size

lugs on the front of the bolt as in the Browning BBR and

the Weatherby Mark V.

There are bolt-actions such as the Winchester M 67 .22 cal-

iber and similar rifles where the locking lug is the butt of

the bolt handle. Then there’s the Winchester M 52, which

has screw-adjustable headspace from an adjustable locking

face in the bolt handle. I could go on, but I think the point

is evident.

Common Causes of Problems

Problems with bolt-actions usually stem from crud, weak

springs, loose screws, broken firing pins, or firing pin screws.

Safeties, improperly converted to clear telescopes, are also

high on the list of bolt-action problems.

Extractor Problems

Broken, worn, or weakened extractors are also common

bolt-action problems, as are broken ejectors. You can easily

replace the Mauser-type extractors or you can weld up

and resharpen them if the claws are worn or broken. You

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must heat-treat them to harden them, so use carbon steel

that will harden as suggested in the section on general

troubleshooting.

Mauser-type ejectors are studs that run in a lengthwise slot

in the bolt. When the extractor pulls the fired case to the

ejection point, the ejector strikes the cartridge head and

knocks it loose from the grip of the extractor.

Remington and other bolt-actions that feature the enclosed

case head use a recessed, spring-loaded pin, which is inside

the ring-shaped extractor. The ring extractor holds the case

in place until it reaches the rear limit of travel of the bolt and

then the pin flips the case free of the action.

The Ruger M 77 uses a Mauser type extractor with a spring-

loaded, pin-type ejector. Some bolt-actions use twin claws set

into the sides of the bolt and held in place with a pin instead

of the extractor ring as with the Mauser and many others.

The principle is the same as the other claw types. Most bolt-

action extractors and ejectors will come under one of these

types.

As noted earlier, there are just too many different bolt-action

rifles to explain all of the variations in this size book.

Firing Pin Problems

Firing pins are sometimes broken in all types of actions and

the bolt-action firing pins are generally easier to replace. In

the military types, the rear of the bolt screws off so you can

pull out and easily replace the firing pin. They’re generally

held in place by the tension of the firing pin spring just as

they are in the Springfield and most other military rifles.

Warning: Exercise extreme caution when replacing a firing

pin. Make certain that a replaced firing pin doesn’t extend

too far into the chamber (in either the battery or retracted

position) or travel too far forward when struck by the striker.

A firing pin that extends too far forward will rupture the

primer and release hot powder gases into the rifle action.

Also, the firing pin may remain in the primer and prevent the

case from ejecting. The coil springs used in bolt-action rifles

are very durable, but occasionally one will become weakened

by the rifle having been allowed to sit cocked for too long a

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period. The replacement is easy, but sometimes you have to

thrust a pin through a hole in the striker to hold the spring

while you screw on the rear of the bolt. The new spring may

seem too long, but will gradually shorten, or “set” as time

passes. Don’t shorten the replacement spring unless you

absolutely can’t get it into place.

Note: The bolt handle must remain in the cammed or “up”

position while you remove it from the rifle for cleaning and/

or other purposes. There should be a tiny detent to assure

this. If it slips and comes uncocked, you’ll have to rotate the

bolt handle to get the bolt back into the rifle. The rotation

operation usually requires a vise or some way to hold the

bolt firmly so that you can rotate the handle to cam the firing

pin back against the spring tension.

The U.S. M1917 Enfield rifle cocks on the closing stroke.

Most shooters don’t like this feature and will buy a kit to

convert the bolt to cock on the opening stroke when the bolt

handle is lifted. Installing the kit is a straightforward proce-

dure, but it’s very important to ensure that the cocking cam

won’t slip and let the firing pin come forward. If this occurs,

the bolt will close with the firing pin protruding into the

chamber. Here it will strike the primer of a round in the

chamber and possibly set it off without the bolt handle being

locked.

I experienced this once when I suddenly found I couldn’t

close the bolt on an Enfield that I had converted to cock on

the opening stroke with a kit sold for this purpose. I was

groundhog shooting one evening and when I fired at one pig,

another one popped up and made an excellent target. I threw

another round into the chamber and tried to get the bolt

closed. It wouldn’t close even when I tried to force it with the

bolt handle. I looked to see the problem and found that the

gun had come uncocked. I was trying to force the bolt closed

with the firing pin protruding into the primer of the round in

the chamber! When I saw what had happened and noticed the

fairly deep indentation the firing pin had made in the primer

of the loaded round, I felt the hair on my neck stand up. I

will never know what kept the rifle from firing, except that

possibly the spring was able to cushion the shock when the

bolt closed. I’m forever grateful that it didn’t fire because I

would have had a bolt through the head if it had. I’ve always

felt that “someone up there” was watching over me that day.

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Bolt-action Safeties

In my opinion, bolt-action safeties are the most positive of all

the different action types. The Mauser type has a lock that

cams down into the rear of the firing pin striker and makes

it impossible for the gun to fire without taking off the safety.

The Enfield, Springfield, and many others have the same

almost foolproof safety. The Winchester M 70 is also a very

safe type as are the Ruger and Browning.

When converting military rifles to sporters, it’s necessary to

change the original safeties so they won’t interfere with

mounting a scope. You can convert the Springfield and

Mauser safeties to clear a scope by either of the following

ways. You can weld on a safety lever at an angle to the

original or buy and install a safety conversion kit such as

that offered by Brownells.

Grease and Crud Build-up within the Bolt

One final problem with bolt-actions concerns grease and

crud build-up, which is usually not a major problem until

cold weather stiffens them up. You can avoid grease and

crud build-up by using a light machine oil in the rifle bolt.

Then you won’t miss that nice buck one cold morning when

your firing pin striker slows down from stiff grease and crud

and fails to strike the primer hard enough to fire the gun.

Final Thoughts on Bolt-actions

If I were to select one bolt-action as the all-time greatest, it

would have to be the Winchester Model 52 Sporter in caliber

.22 long-rifle rimfire (Figure 66). I have one, which when firing

Eley Match ammunition, will produce five shot groups meas-

uring about .140 inches over bullet diameter at 50 yards.

Semiautomatic Rifles

World War II did for the semiautomatic rifle what World War I

accomplished for the bolt-action repeater. Those accustomed to

bolt- and lever-actions gained respect for the semiautomatic

rifle through use of the M1 Garand and M1 carbine. Today

the “old” Garand is all but obsolete, yet it paved the way for

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Rifles 107

several centerfire (including magnum variety) semiautomatic

rifles plus a myriad of .22 rimfire designs.

Probably the first “example” of a true auto-loading design

was the brainchild of John Moses Browning. He mounted a

paddle to the front of a Winchester Model 73 rifle and linked

it to the lever mechanism. The force of gases exiting from the

muzzle pushed the paddle, thereby operating the 73’s lever

“automatically.” From this basic start, Browning eventually

invented several different types of semiautomatic mechanisms

that he incorporated in his shotgun and machine gun designs.

The difference between an auto-loading firearm and other

designs is the eight functions, only firing is performed

manually. The rifle performs the other seven automatically,

permitting the shooter to concern him or herself only with

aiming and squeezing the trigger. For this reason, semiauto-

matic sporting firearms, usually referred to by the misnomer

“automatics,” are quite popular. A succession of shots is

seldom necessary in the game field, but the relative ease of

operation and knowing those follow-up shots are there has

“sold” the self-loader to many hunters. There are three basic

groups of semiautomatic designs:

1. Gas-operated

2. Recoil-operated

3. Blowback

FIGURE 66—The Winchester M 52 Sporter is unquestionably the finest .22 rimfire rifle of all time. Notice its Leupold Vari-X III 4X compact scope—a truly fine rifle for both small game and targets.

Gas-operated Design

The most familiar type of selfloading or semiautomatic action

is the gas-operated, of which there are two subdivisions:

(1) the long-stroke system and (2) the short-stroke system.

The M1 Garand and the M1 carbine of World War II, both

gas-operated, are examples of each type (Figures 67, 68, and

69). The Garand uses a long-stroke system where gas vented

off near the muzzle activates a piston with a long operating

rod that in turn activates the action.

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FIGURE 67—U.S. Rifle Cal. .30 M1 Garand (Photo supplied by Reinhart Fajen, Inc.)

FIGURE 68—U.S. Carbine Cal. .30 M1

FIGURE 69—Operation of the U.S. Carbine M1. Unlike the Garand, gas vents into a cylinder midway down thebarrel. Cutaway shows the bullet just passing over the gas vent port. The action is still locked. Although Garandand M1 cartridges are of the same caliber, the cases and ballistics are vastly different.

Rifles 109

The M1 carbine and many modern auto loaders use the

short-stroke gas system. In the short-stroke gas system, the

gas vents through a port midway down the barrel and into a

gas cylinder where it activates a short-stroke piston moving

only about a quarter of an inch. The short movement of the

piston is transmitted to an operating rod or arm, which then

opens and operates the bolt.

In all gas-operated semiautomatic arms, the action opens

by the force of the explosion (gases), and closes by strong

springs compressed by the gas.

Recoil-operated Design

The second type of semiautomatic operation is by recoil, and

there are two types: long recoil and short recoil.

The long-recoil design has been in use for more than 50

years, and is a solid, dependable system, used primarily in

shotguns and pistols. (Centerfire rifle cartridges generate too

much pressure for the design principle.) A disadvantage is

the “double slam,” annoying to many shooters, when the

recoiling barrel adds a second jolt to the primary recoil.

The Long-recoil design. Long recoil is so called because the

barrel and bolt (breech block), securely locked together, recoil

farther than the length of the cartridge—usually three to four

inches. The bolt temporarily locks at the rear of the action

while the barrel, under the impetus of compressed springs,

moves forward. The fired case, secured to the breech bolt by

the extractor, ejects when the barrel starts its forward

motion. Upon return to battery (firing position), the barrel

trips a lever, which unlocks the breech bolt. The bolt then

moves forward, picking up a new cartridge and chambering

it as the bolt slams home (Figures 70 and 71).

In years past, Remington made several long-recoil operated

rifles, notably their Model 8 and Model 81.These arms were

distinguished by a heavy barrel shroud or sleeve that con-

tained the arresting mechanism into which the barrel recoiled.

Such an arrangement had a bad effect on accuracy. Another

drawback that led to the long recoil’s early demise, aside from

being difficult to work on and hard to keep operating, was

the fact that they were generally limited to medium-powered

.30-30 class ammunition. (The Model 81, however, was also

chambered for the .300 Savage, a more powerful cartridge

approximating early .30/06 performance.)

Arms of the long-recoil design are the familiar “Hump Back”

Browning auto-loading shotgun and other similar shotguns

made by Remington, Savage, and Breda and Franchi of Italy.

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FIGURE 70—Shown is an exploded view of a rifle at the moment of firing. The spring within the plunger tubedrives the hammer forward, thus driving the firing pin into the primer. The action is still locked. The bullet is stillin the barrel and gas behind the bullet is entering the gas vent port where it will activate the piston.

FIGURE 71—The bolt has been unlocked and driven back by the operating rod. The spring-loaded ejector pivots thefired case out of the rifle. The hammer has been forced back and cocked and a new cartridge rises into position for chambering. The bolt assembly, rebounding forward against spring tension, will strip off and chamber the nextcartridge.

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The Short-recoil design. Short-recoil designed firearms

also incorporate the breech bolt locked-to-barrel system of

the long-recoil design, in which the bolt and barrel recoil

together when the gun fires, thus compressing a recoil

spring. However, the barrel stops moving after only a short

distance (1/4 to 3/8 inch) and unlocks from the breech block.

Gas pressure and inertia then carry the breech block fully to

the rear until stopped by a buffer spring. The breech block

rebounds forward, picks up and chambers the next cartridge,

and is ready for firing.

The short-recoil system is usually used in handguns (the

famous Colt .45 M1911 is a prime example), but it was also

employed in the Johnson semiautomatic rifle of World War II

and in the comparatively recent Browning double-automatic

shotgun.

Blowback Design

In the blowback design, the barrel remains stationary while

the bolt or breech block moves to the rear under the impetus

of push from the exploding cartridge. There’s no connection

or linkage between the barrel and breech block. Timing is

dependent upon gas pressure, weight of the breech block,

and/or springs designed to hold the breech block in place

against the cartridge. Thus, blowback-operated systems

function through manipulation of the laws of inertia.

Arms that utilize the blowback design are usually low powered,

requiring a relatively short breech block movement. The only

centerfire rifles of blowback operation that come to mind are

Winchester’s semiautomatic .351 and .401-caliber models,

which many police departments use.

The Thompson submachine gun, and in fact most subma-

chine guns, are simple blowback-design weapons in which a

massive chunk of metal is used as a breech bolt that’s driven

rearward by the force of the burning gases. Since the breech

bolt is quite large, substantial inertia (the tendency of a body

at rest to remain at rest) must be overcome. By the time

the bolt starts to move to the rear and allow gas to escape,

the bullet is already out of the barrel. Moving forward, the

bolt cocks the action, then picks up and chambers a fresh

cartridge.

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Some blowback semiautomatics, when incorrectly assembled

or with badly worn parts, can fire fully automatic, constituting

dangerous and highly illegal firearms. Most, however, incor-

porate a “disconnector” that holds the hammer back and

prevents it from following the bolt to firing position, thus

making a separate trigger pull necessary for each shot.

Most .22 rifles in semiautomatic design are blowback-operated,

as are most low- to medium-powered handguns. We haven’t

found this system practical for high-powered rifles since the

comparatively large breech bolt required would result in an

unbelievably cumbersome, unwieldy, and heavy rifle. It has

been calculated that a .30/06 of blowback design would

require a breech block weighing about 27 pounds!

Note: Locking and unlocking in the usual sense is omitted in

most blowback designs.

Sequence of the Eight Functions inAutoloading RiflesFor purposes of explanation, we’ll discuss the popular

Remington 742 semiautomatic rifle. Its operation is typical of

all gas-operated semiautomatics, whether of short- or long-

stroke design.

1. As the shooter pulls the trigger, the sear disengages from

the hammer notch, permitting the hammer to rap the

firing pin, which then strikes the cartridge primer,

(1) FIRING the gun. Following passage of the bullet over

the gas port midway down the barrel, expanding gases

are metered through the port and downward into the

gas or impulse chamber.

2. This gas pressure acts against a small piston, which

forces the action bar and bolt assembly to the rear,

thus compressing the action spring. As it starts moving,

the bolt (2) UNLOCKS and the cartridge case is

(3) EXTRACTED from the chamber. Moving backward,

the bolt compresses the hammer spring, accomplishing

(4) COCKING. As the bolt stops, the ejector pin tips the

case from the action, thus (5) EJECTING the fired car-

tridge. This clears the path for the next cartridge, which,

under pressure of the magazine spring, has risen into

(6) FEEDING position.

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3. The compressed recoil spring now forces the bolt

forward. It strips the in-position cartridge from the

magazine and forces it into the chamber, thus

(7) CHAMBERING. As the bolt closes firmly, the

lugs rotate, (8) LOCKING. The sequence repeats

automatically following each manual trigger let-off.

Winchester’s semiautomatic sporter, the Model 100, has a

unique self-metering gas system (within the cylinder) that

incorporates a cup-shaped piston facing the muzzle of the

rifle. This cup has a small hole that matches up with the

vent hole in the barrel. After sufficient expanding gases have

entered the two matching holes to operate the action, the

piston cup moves to the rear and cuts off the gas supply.

This self-metering device eliminates “pounding” and makes

for a smoother operating action.

The new Browning semiautomatic sporting rifle, first market-

ed in 1967, has an operating mechanism very similar to that

of the M1 carbine, in which a short-stroke piston operates

the action system.

By way of contrast, the M1 Garand takes its gas from a port

very close to the muzzle. It was originally thought that the

lessened gas pressure at that point would exert a longer,

slower push against the piston and minimize “slamming.”

A long operating rod was required, which caused other

problems and now doesn’t exist in more recent designs.

Troubleshooting Semiautomatic RiflesAn even greater variety of semiautomatic rifles is available

than bolt-action rifles. The Remington M 742 and newer

Models Four and 7400, the Browning BAR, and assorted mil-

itary-style rifles are gaining in popularity every day.

Caution: You should have a reference manual for any semi-

automatic rifle you work on. Obviously, it’s helpful to have a

reference manual available when working on any firearm, but

most especially when working on the three semiautomatics

listed above. They offer many chances for making mistakes,

which can cause serious trouble (Figure 72).

An acquaintance in Williamsport, MD, told me the following

story. My friend was experiencing difficulty opening a Franchi

M 500 12 gauge, five-shot automatic after firing it, so he

pried the bolt back with a screwdriver and unloaded the gun.

Then he worked the action. It seemed to free up and work

just fine, so he and his friends decided to continue their

rabbit hunt. First, he filled the magazine; then, he dropped

a loaded shell into the chamber and pressed the bolt release

button. A roar he described as “one long bang” tore the gun

from his hands and thrashed it against his face.

The gun had emptied the magazine so fast it sounded like

one explosion. The firing pin was stuck forward and the gun

fired, like most machine guns, from an open bolt. He said

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FIGURE 72—Exploded View of a Semiautomatic Action Rifle

Rifles 115

that anyone standing to his right would have been killed as

the gun spun to the right.

The story is something to think about at the very least. It

reminds me that a malfunctioning semiautomatic can be

a deadly machine. This is good reason to be extra careful

when working on the semiautomatics.

Crud

Again, crud causes the most problems. Crud is even worse

in semiautomatics because the gas pistons must be clean

and free of corrosion for the guns to operate well.

Broken Extractors

Besides crud, probably the worst offenders are worn or broken

extractors. Replacing broken extractors in the rifles we’re

discussing is no real problem.

Stuck Cartridges

The real problem comes when the head comes off a case and

leaves part of the case in the chamber. This precludes tap-

ping it out from the muzzle with a cleaning rod, as it’s diffi-

cult to get into the breech without complete disassembly of

the rifle. What should you do? Possibly, you could screw a

suitable size thread-cutting tap with a long “lead” or tapered

portion on the nose into the remaining brass. This would

furnish a shoulder against which you could drive a ramrod

to move the remaining portion of the case in the chamber.

Use a telescope gage to determine the inside diameter of

the remaining portion of the brass case and select the proper

size tap. It may be necessary to slightly grind the tap.

However, you should be able to get four turns on a fine

(NF) tap. Use a small ratchet wrench to turn the tap.

Note: Be careful not to turn the tap so far as to cut through

the brass and damage the chamber wall. When the tap is

in far enough for a good bite, put the ramrod through from

the muzzle and drive the stuck case out by driving against

the tap.

Rough Chamber Walls

One of the primary reasons for stuck cases is rough chamber

walls. You can polish the chamber walls by using a hacksaw

to slit about three inches of a short section of hickory ramrod

and folding a piece of garnet cloth so the cutting side is out.

Insert the Garnet cloth in the slit in the wooden ramrod

section.

Note: You can do the work from the muzzle end if you use a

long enough section of ramrod, but I prefer to disassemble

the rifle and do it from the breech end.

You fasten the ramrod in the chuck of a hand drill, which

you use to spin the rod with polishing cloth in the chamber.

If the chamber is very rough, you may wish to start with

coarser polishing cloth and finish with the garnet cloth. Such

a polishing will make extraction much easier and eliminate

most extraction problems.

Clip Feeding

Sometimes feeding cases from clips cause difficulty in rifles

like the Winchester M 77. Close up the front lips of the clip

if the loaded cartridge is hitting too high above the chamber.

If it is striking below the chamber, you can open the clip up

a bit to allow the case to hit higher. Often, polishing the feed-

ing ramp on self loaders will improve ammo feeding.

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Rifles 117

Self-Check 7

Fill in the blanks in the following statements.

1. The Remington _______ is the only slide-action rifle to handle such high-intensity cartridges as the .30/06, .270, .308., etc.

2. The first really successful bolt-action design was the 11mm Mauser single-shot of 1871,which employed a true _______ design.

3. There are three basic groups of semiautomatic designs: _______ , _______ , and _______.

4. The difference between an auto-loading firearm and other designs is that of the eightfunctions, only one is performed manually and that is _______.

5. The Remington 760, essentially a Mauser turning-bolt design, has a _______ lockup.

Check your answers with those on page 130.

DOUBLE RIFLES

You won’t see too many double rifles (double-barrel rifles).

Although not common in this country, a surprising number

of these old-timers do turn up for needed repairs and adjust-

ments. The true double rifle looks much like a side-by-side

shotgun. It’s usually based on the same hinged breech

design (but beefed up) and has a shotgun-type extractor.

There the similarity ends.

A double rifle is actually two rifles in one, with separate

triggers and locks. If one malfunctions, the other can still

work. Don’t confuse double rifles with the European Drilling,

essentially a side-by-side double shotgun with a single slen-

der rifle barrel mounted under the tubes.

The double rifle is essentially a British specialty and has

never been popular in the United States. Only a small num-

ber were ever built in the United States. There was never a

real need for double rifles and the big drawback was their

high production costs (Figure 73). The twin rifle bores had

to be adjusted until shots from both barrels converged at the

same point—usually 50 to 100 yards. Adjusting the barrels

took many painstaking hours and frequently days by a master

armorer soldering, firing, resoldering ad infinitum. Most dou-

ble rifles were designed to stop a charging elephant. When

the time came to use the rifle for such a purpose, accuracy

had to be good—superior to the “accuracy” provided by double-

barrel shotguns with slugs printing perhaps a foot apart at

50 yards.

It would be impossible to manufacture double rifles today at

a price that would bring enough sales to warrant production.

Double-barreled rifles were, however, fairly common in the

black powder era for a brief time. None of the manufacturers

of double rifles stayed in business more than a few years.

The L. C. Smith Company, makers of a fine double shotgun,

also manufactured double-barrel rifles for a short time in

limited quantity. Winchester made at least one Model 21 in a

double rifle configuration, but such a firearm has never really

caught on in the United States.

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Rifles 119

Most double rifles have traditionally been made in England,

Belgium, Germany, and Austria, where a few are still being

manufactured, primarily for hunters pursuing large, heavy,

dangerous game in Africa or India. Even though the double

rifle’s price is astronomical, the waiting list to purchase it is

long, with delivery scheduled from six months to as long as

two years.

Double rifles have always received the utmost attention,

respect, and care in areas such as Africa, where hunters of

elephant, rhino, Cape buffalo, and lion used them for many

years. Around the turn of the century, the bolt-action

repeaters of the time couldn’t use the exceedingly long, pow-

erful “African” cartridges. Therefore, heavy .40 to .60 caliber

double rifles, were introduced. No repeating rifles could (or

can) deliver a second shot faster and with less possibility of

malfunction. These double rifles were chambered for many

different types of cartridges, including the long-defunct black

powder types. Many were made with Damascus barrels, suit-

able for black powder loads only. You should treat any such

firearm coming into your gun shop for repair with great

respect. Almost without exception, double rifles are valuable

as functioning firearms or as collector’s pieces (which, indeed,

most are).

FIGURE 73—Fine double rifles are usually lavishly checkered and engraved, sometimes costing more than $5,000.

Rifles

Troubleshooting Double-barrel Rifles

Troubleshooting technique for double-barrel rifles is the

same as for double-barrel shotguns. Double-barrel rifles have

the same function and parts, such as the standing breech,

water table, pivot pin, and lock types, which are identical in

both. The only difference is that the rifles are heavier and

stronger in order to withstand the much higher pressure

loadings.

As already mentioned, regulation of the barrels is critical. If

two barrels aren’t shooting to the same point, it’s necessary

to heat them enough to soften the solder, move them a bit,

and resolder. A heavy steel frame known as a regulating

mount holds the barrels with clamps during resoldering.

Note: The study unit Shotguns gives more troubleshooting

details.

Single-shot Actions

Few rifle enthusiasts today give more than a passing thought

to how significantly the “lowly” single-shot breech-loading

rifle influenced and changed the course of history.

In the 1850s through the 1870s, the “new” breechloaders,

with their comparatively rapid reloading capability, provided

military supremacy for many armies that faced (and defeated)

other armies equipped with slow-firing muzzleloaders.

Hunters swept clean the North American prairies of buffalo

with powerful, long-range, single-shot Sharps and Remington

rolling-block rifles, some equipped with primitive, yet effec-

tive, telescopic sights.

The Dropping (or Falling) Block Design

The direct ancestor of most modern single-shots was the

Sharps rifle developed by Christian Sharps during the 1840s,

when percussion ignition largely replaced flintlocks. The

Sharps rifle was to single-shots what the Mauser was to

bolt-actions. Sharps’ dropping-block design, in which the

breech block rose and dropped vertically in mortises milled

in the receiver walls, was exceptionally strong and provided

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Rifles 121

a perfect gas seal. Thousands of Sharps rifles were success-

fully converted to metallic rimfire and centerfire cartridges.

The Sharps rifles were originally designed for breechloading

of paper bags containing powder and projectile, which were

sheared at the tail by the rising block, thus exposing powder.

The original Sharps exposed-hammer design gave way to a

number of hammerless (concealed in frame) variations,

including the Sharps-Borchardt of 1870, the match-winning

American Ballards, the British Farquharson, and the famous

Stevens “Ideals.”

Probably the best-known Sharps progeny was the Winchester

single-shot of 1879, one of John Browning’s first designs sold

to Winchester (Figure 74). It was made in many different

forms for different cartridges, with the various designs known

as high-wall, low-wall, thick-wall, and thin-wall (referring to

receiver dimensions, of course).

Basically Lever-action Single-shots

All Sharps-inspired or derived designs were essentially single-

shot, lever-action rifles in that a pivoting trigger guard or

lever behind the guard operated the action. Moving the lever

forward dropped the breech block and exposed the chamber

for loading the cartridge. After firing, extraction (and some-

times ejection) occurred by opening and/or “snapping” the

lever (Figure 75).

Today, perhaps because of the nostalgia craze, single-shots

are again in big demand from hunters and shooters wanting

to “relive” the past and/or give game a better break.

FIGURE 74—Shown is Winchester’s world-famous dropping-block single-shot designed by John Moses Browning.

Modern centerfire one-at-a-timers include the Ruger No. 1,

similar in appearance to the handsome and venerable British

Farquharson, but greatly improved mechanically; and the

Browning single-shot, basically a modified Winchester Hi-Wall.

Rolling-block Design

Like the Peabody action, best known as the Martini, the

Rider rolling-block system was invented by one man, Leonard

Gieger. It then became famous through the modifications of

another, Joseph Ryder, or Rider (Figures 76 and 77). Both

men had patents on a similar rolling-block design, but

Gieger’s was the true basis of the Remington rolling block

(Figure 78). Ryder, employed by Remington, slightly changed

Gieger’s design for production (Remington had purchased

both patents).

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FIGURE 75—Two Modern Single-shot Rifles. Top: New Browning, Bottom: Ruger No. 1.

Rifles 123

The rolling-block design is the simplest of all single-shots

(Figure 79). The design is enormously strong and consists

basically of two pivoting breech-locking mechanisms, one

mounted behind the other. The mechanisms are attached

to the frame by large axis pins.

The primary mechanism is the breech block, pierced and

containing the firing pin. When the shooter cocks the hammer

back, the firing pin can be rolled up (and down) from the

chamber by means of a thumb spur or extension. When flush

against the chamber, the breech block is spring supported,

but not locked into place.

The second mechanism is the hammer, mounted behind

the breech block, also by an axis pin. When the hammer

is cocked back and the breech block is rolled up against

FIGURE 76—Here’s the Peabody tipping-blockmechanism showing the principle of operation.

FIGURE 77—Shown is the Martini-Henrymechanism illustrating the variation andimprovement of the basic Peabody design.

FIGURE 78—Replica Rolling-block Baby Carbine by Navy Arms

FIGURE 79—Cutaway View ofthe Remington Rolling-blockSystem Showing the Breech-locking Mechanism at Momentof Firing

the chamber (two separate operations), the rifle is ready to

fire. Release of the trigger lets the hammer fall. However,

before the hammer can strike the firing pin, a projection

under the surface of the hammer assembly slides smoothly

into place behind and under the breech block. This locks the

breech bolt firmly against the chamber, a split second before

the hammer hits the firing pin.

The Remington rolling block wasn’t perfected until just after

the Civil War and the United States Army never adopted it.

However, the U.S. Navy ordered 12,000 rifles in 1867. Also,

more than one million RB military rifles and carbines in

7mm (7 � 57), .45/70, and other calibers were sold to

Denmark, Sweden, Norway, Spain, Egypt, Argentina, China,

and other countries, primarily between 1867 and 1879. Its

popularity was short-lived, however, as the first bolt-action

Mauser was just over the horizon, appearing in 1881.

In the 1950s, the United States imported “surplus”

Remington rolling blocks by the tens of thousands, with

prime specimens selling for as little as $9.95. One intrepid

West Coast importer advertised them “complete with plans

for making a rolling-block rifle Moor lamp,” for $7.95. Today

replicas made by Navy Arms are selling very well at $150

U.S. dollars!

While seldom used for sporter conversions, authentic rolling-

blocks are fast becoming collector’s items.

The Sequence of the Eight Functions inSingle-shot Rifles

If you were to hold an empty Ruger No. 1 single-shot rifle

in your left forehand, push down on the lever release, which

is spring-loaded and located immediately behind the trigger

guard, and then push the lever down and forward, you would

accomplish the following.

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Rifles 125

The gun is (1) COCKED as the striker mechanism pushes

back against the spring tension of the mainspring until the

sear catches and holds the striker. While being cocked, the

action is also being (2) UNLOCKED as the breech block

drops, exposing the chamber for feeding and loading. Here,

(3) FEEDING is by hand, and the cartridge is usually

(4) CHAMBERED manually. As the lever is brought back up,

the block rises behind the cartridge, thus (5) LOCKING the

action. The rifle is now ready to fire. After (6) FIRING, the

lever is moved down and forward, dropping the breech block

in its mortise and, depending upon how the user has set the

ejector/extractor mechanism, the cartridge is (7) EXTRACTED

and (8) EJECTED from the gun. Actually, after the shell is

extracted about 1/4 inch, the ejector kicks it from the gun.

Troubleshooting Single-shot Rifles

Procedures for troubleshooting single-shot actions depend

on the type of action involved. The single-shot classification

includes representatives of every type action. Also, you’ll find

some actions, such as the falling-block, only in single-shot

rifles.

Action types include bolt, lever, tip up, falling block, rolling

block, side break, and trapdoor to name some of the most

common. Where applicable, consult troubleshooting instruc-

tions already provided for an action type. Further information

specific to certain action types follows (Figure 80).

Trapdoor Rifles

The trapdoor rifle operates from a section of breech, which is

hinged like a trapdoor that lifts up and is locked by a latch

at the rear. The action is a very weak. The only ones made

were the Springfield army rifles, which were chambered for

the .45-70, .45-90, and .50-70. There are many trapdoor

rifles around, although they have appreciated so much in

value as collectors’ items that very few people will take them

into the woods to hunt with them. I killed my first deer with

a Springfield trapdoor rifle chambered for .45-70 using a 405

grain bullet at around 1,200 fps. It’s important that only

loads listed for the trapdoor rifles be fired in them. There are

loads for the Marlin .45-70 rifles that will completely wreck

a trapdoor model and likely severely injure the person who

fires the load. These were black powder rifles and won’t

handle smokeless powder pressures.

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FIGURE 80—Exploded View of a Single-shot Action Rifle

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The critical maintenance is to make sure the dog latch is

seating all the way down and that the hinge pin at the front

of the trap is in good condition.

Falling-block Designs

Falling-block rifles work on the same principle as a breech

block, which cams into position at the rear of the bore. They

also operate on the Sharps’ principle in which a breech block

slides up and down in a box space as a lever below the breech

operates it. The lever also usually acts as the trigger guard.

The only maintenance is to keep the breech greased where

the block slides. Also, keep the hinge pins well oiled and in

good condition.

The Tipping-block Design

The tip-up action is just like a single-shot, top-break shot-

gun. The barrel tilts down from a hinge in front of the water

table, and the firing pin is inside the standing breech.

Maintenance is the same as a tip-up shotgun.

The Side-break Design

The side-break action is like a tip-up except that the barrel

moves to the side to clear the standing breech and allow

loading and extraction. Stevens made the side-break for a

short time.

The Rolling-block Design

Maintenance of the rolling block is easy as it has only four

moving parts. You must keep the heavy breech block and

hammer screws/axles well oiled. The extractor seems to wear

fast. You can easily make the extractor from scrap metal in a

couple of hours. Other than occasional firing pin replacement,

this is about all the maintenance required to keep a rolling

block rolling.

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Self-Check 8

Indicate whether the following statements are True or False.

_____1. The prairies of North America were swept clean of buffalo with powerful, long-range,single-shot Sharps and Remington rolling-block rifles—some equipped with primitive,yet effective, telescopic sights.

_____2. Maintenance of the rolling block is easy, with only eight moving parts.

_____3. The rolling-block design is the most complicated of all single-shot rifles.

_____4. Probably the best known Sharps progeny was the Winchester single-shot of 1879,one of John Browning’s first designs sold to Winchester.

_____5. Troubleshooting technique for double-barrel rifles is the same as for double-barrelshotguns.

Check your answers with those on page 130.

129

Self-Check 1

1. False. The Jaeger was short barreled and had a short,

heavy stock.

2. False. The wheel-lock allowed for better accuracy.

3. True

4. False. A caliber is .01 inch.

5. True

Self-Check 2

1. never

2. accuracy

3. abrasions

4. pivot point

5. gas cutting

Self-Check 3

1. True

2. True

3. False. You can use longer barrels.

4. True

5. False. A barrel’s weight, diameter, and stiffness are all

important to a rifle’s accuracy.

Self-Check 4

1. True

2. False. Stainless steel isn’t rustproof.

3. False. The extrusion process weakens the steel.

4. True

5. False. Barrel straightening is accomplished by placing

the barrel across two heavy steel fingers and applying

pressure to it between the support points.

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Self-Check Answers130

Self-Check 5

1. Creep

2. half-cock

3. liability

4. aftermarket

5. case hardened

Self-Check 6

1. True

2. True

3. True

4. False. The lockup is like the multilug bolt-actions.

5. True

Self-Check 7

1. 760 “Gamemaster”

2. turning-bolt

3. gas-operated, recoil-operated, blowback

4. firing

5. multiple-lug

Self-Check 8

1. True

2. False. It has only four moving parts.

3. False. The rolling-block design is the simplest of all single-

shot rifles.

4. True

5. True

Examination 131

925 Oak Street

Scranton, Pennsylvania 18515-0001

Rifles

When you feel confident that you have mastered the material in this study unit, complete the following examination. Then submitonly your answers to the school for grading, using one of the exami-nation answer options described in your “Test Materials” envelope.Send your answers for this examination as soon as you complete it.Do not wait until another examination is ready.

Questions 1–20: Select the one best answer to each question.

1. The primary advantage of the multiple locking lug design overthe single locking lug is

A. shorter bolt lift.B. decreases in bolt handle and scope bell clearance.C. an increase in bolt locking strength.D. faster repeat shots.

2. How many times in 50 yards should a bullet spin when fired froma barrel that has a 1 inch in 12 inches rifling twist?

A. 50 C. 150B. 62 D. 600

3. You can greatly lessen bore erosion by using

A. lighter-than-maximum loads.B. reloads.C. heavy loads to clean out the barrel.D. new brass only.

EXAMINATION NUMBER:

02530501Whichever method you use in submitting your exam

answers to the school, you must use the number above.

For the quickest test results, go to http://www.takeexamsonline.com

Ex

am

ina

tion

Ex

am

ina

tion

Examination132

4. What rifle had the first ignition system that was dependable in bad weather?

A. Jaeger C. SnaphaunceB. Matchlock D. Caplock

5. The rear diameter of a barrel is generally determined by the

A. caliber. C. type of barrel.B. size of action. D. barrel length.

6. The shock waves along the length of the barrel are called

A. rifling. C. bullet yaw.B. nodes of vibration. D. the Coriolis effect.

7. The actual weight of a barrel is determined by the caliber (bore diameter) and the

A. cartridge size. C. outside diameter.B. bullet weight. D. type of metal finish used.

8. You should lap a barrel to

A. make the bore smaller. C. restore accuracy.B. make the rifle shoot harder. D. reduce rifling.

9. Gas ports are engineered into the modern rifle to

A. reduce chamber pressure. C. increase velocity.B. reduce recoil. D. protect the shooter.

10. The most popular barrel length of centerfire rifles is

A. 20 inches. C. 28 inches.B. 24 inches. D. 30 inches.

11. The famous Kentucky Rifle was actually the

A. Massachusetts Rifle. C. Virginia Rifle.B. Pennsylvania Rifle. D. Mississippi Rifle.

12. The first rifled barrels were probably made in

A. England. C. France.B. Italy. D. Germany.

13. The optimum method for preventing burrs inside the bore when machining recoil compen-sating ports into the barrel is to use

A. a hack saw. C. an electric discharge machine.B. a drill press. D. a rat tail file.

Examination 133

14. _______ steel is the type used in most gun barrels intended for use with today’s high-powercartridges.

A. Ordnance C. NickelB. Stainless D. Gun barrel grade

15. A good pull weight for triggers on hunting rifles is in the

A. 10 to 15 ounce range. C. 50 to 75 ounce range.B. 25 to 40 ounce range. D. 80 to 100 ounce range.

16. A floated barrel is one that

A. rests on the stock only at the forend tip and receiver ring.B. is fully bedded for the entire length of the stock.C. doesn’t touch the stock forward of the receiver ring.D. won’t experience nodes of vibration.

17. You can best counter gas cutting in barrels by

A. using undersized bullets.B. using black powder.C. using properly sized, well-made bullets.D. using lead bullets.

18. The first gun barrels were probably made of

A. stone. C. iron.B. bamboo. D. copper.

19. Bullet yaw is the term used to describe a bullet’s

A. velocity.B. disintegration ratio.C. travel in a spiral course around its true bullet path.D. impact power.

20. A .40 caliber muzzle-loading rifle has a land diameter of

A. .004 inch. C. .100 inch.B. .040 inch. D. .400 inch.