Muzzleloader Barrel Machine

by Gerald R. Hunter Georgia

There are several gunshops in this country which can turn out an excellent rifle barrel or rechoke a shotgun tube to your preferred percentage, but for many muzzle­loaders this is not enough. It wasn't enough for me, when I bought a bucketful of flintlock parts from Dixie Gun Works, induding an unrifled barrel blank.

Of course, many a muzzleloader who would give his eyeteeth to be shooting a rifle barrel he had built himself, may be well heeled, but there are also many poverty­stricken ones who cannot afford such custom work. The barrel machine described and pictured here, of my own design, is versatile, accurate, minimal in cost, and small enough to fit into the tiniest home workshop.

Among the many operations which can be performed on the device are rifling, overboring, finish reaming to land size, chambering, throating and muzzle-relieving of rifle barrels, as well as choke cutting, chambering, lap­ping and polishing of shotgun bores.

The rifling rig cuts any number of grooves from I to 12 (including the awkward 7 and II) and any pitch from I turn in I foot to infinity in a straight twist (and with an arched cam bar, the gain twist).

While the device could be used for deep-hole drilling in solid blanks, it is intended for overboring shot-out rifle bar­rels, or increasing the bore size of useless calibers to larger conversions like . 357 and .44 magnum, or muzzleloaders. The same unit that does the boring is utilized also for finish reaming after the boring, preparatory to rifljng. In smooth­bore barrels it can be used to remove pitting when thickness of barrel walls allows, to ream out choke, and to rechamber. This same unit is used for all work on rifle barrels except for lapping and cutting the liOing. Shotgun bore work is done on the third unit of the device.

A single motor transmits power through a series of V-belts and pulleys to operate the devices at proper relative speeds. the rifling head is hand-operated, as is the shotgun barrel carriage_ The barrel boring carriage may be hand-operated or powered by cables, pulleys and weights.

Overall size of the composite machine is only 24 It wide by 42' high by 96" long, but it could be smaUer. The ri­fling platform may be swung out about 450 during the brief time when actual ri fling is being done, to make it more comfortable for the operator, and also so the cam bar (which determines twist) has additional room when severe rates of twist are being cut.

Expense "f the machine can vary widely. For instance, the .frame can be made of welded I-beams; expensive thrust bearings can take the loads; highly tempered rack and pinion gears can turn the cutter rod, and so on, to a very staggering figure. To shave costs severely without

sacrificing efficiency, my machine is constructed from materials you would classify as junk. It cost less than $50, excluding the motor.

The most important ingredient is the entire operation is that of proper perspective. You must first understand just what you are doing, what the parts of the machine are to do, and how you are going to make the machine do them. Once you have this' 'big picture" you are in a posi­tion to economize most on construction.

Few of the tolerances are critical. You can vary the di­me�ions of the parts to fit whatever supply of materials you can acquire at least cost. If you can find a cam bar of somewhat different thickness than specified, for in­stance, at a substantially cheaper cost, by all means sub­stitute it. Further savings can be effected by utilizing used materials. Superficial rust on a rail or bar from a scrap­yard may make that material available for JO� per pound instead of several dollars per pound for some newly al­loyed metals, either of which would do the job. In the case of rods, use hot or cold rolled steel instead of drill rod, at vast savings. For the hollow boring rods, use seamless steel tubing instead of the more expensive air­craft qUality. For chucks, borrow those already on hand frc:..m some of your other appliances or machines.

To begin a�[ual construction of the machine, cut the

Act;urau indexing of the rifle barrd vise can be done by using a compollnd

bubble protractor temporarily c1il111ped to pipe that will be the vise,

Compltlld r/fling barrel vlst. insldt Induing head.

4x4's to I�ngth for the main frame, then the 2x2's for the s�condary part. Mortise the joints or half-lap them. and as you join the parts apply glue, true them with a square, clamp them, drill pilot holes, and bolt or screw them to­gether. Allow the glue to dry thoroughly before proceed­ing farther. The machine will be subject to vibration, which will wreck your structure unless it is soundly made.

Do not permanently install th� bed for the lapping! choking device until you have found, by actual �xperi­ment, where it must go to align properly with the chuck.

Rifling Rig Begin with the platform, a 2 x 10 x 96 inch straight, well

seasoned plank, and bolt or screw the tracks on one end of it. Any track that is substantial and reasonably true will do.

Make up the carriage block; and rabbet, dado, or oth­erwise, make it a clean sliding fit in the channels of the track. Length must be provided to give room for the pi­nion gear, rack gear bar, bearings and hand grip.

The ball bearings (roIler skate wheels) must be firmly bolted to the carriage with V-straps, or something simi­lar. Between the bearings, at right angle�, bolt the chan­nel iron guide for the r�ck gear. The rack gear is·a bicycle chain bolted to a flat steel bar that will slide snugly in the greased guide channel.

Anchor the rack gear to the rack gear bar with a stout machine screw at either end, for the bicycle chain must be very taut. The rack should be long enough to all ow two or more complete revolutions of the pinion gear (a bicycle rear sprocket) when assembled and meshed.

The largest rod that will pass through the hole in the sprocket acts as the pinion axle. Turn down ends of the rod to fit through each bearing (the skate wheels), leaving shoulders turned on the rod as natural end stops, and braze the rod true in the sprocket. Before assembling the axle, adapt the longer end of it to hold the rifling rod. A common threaded joint, which allows twisting, wiII not

suffice. You can cut a lap-and-hook joint, held together with a movable sleeve. or a small chuck.

Assemble the sprocket-mounted axle into the bearings, mesh sprocket with the rack gear, then bolt down the bearing housings.

Camming The cam bar, by the angle it forms with the spacing bar,

determines the bore distance per revolution of pitch to be cut, and must be four feet long if you want to cut barrels up to 42". This proportion may be used for shorter lengths. The pivot end is attached to the platform with a bolt; the opera­tor's end is anchored to the spacing bar with any movable device which will securely hold it to the index. Dogleg bends raise the cam and spacing bars up to the level of the rack gear guide so they'll operate in the same plane.

The cam end of the rack is drilled to accept two bolts. A short under bar, 8" long, is drilled and mated to that end of the cam bar, and a ball bearing skate wheel is per­manently bolted under the rack bar and inside the cam bar. The outer holes are elongated to allow adjustment (fast twists cramp the cam), and a second skate wheel is mounted on a wing nut adjustment bolt through the routed holes. The skate wheels must embrace and snugly roll along the cam bar; the wing nut adjustment is neces­sary because the space between the wheels increases as the

•.•• • • .••.• OilLinc:

r!===�·�.� . . i---- - _. Oil Sea! Healing

TranSrerpulle)'. ___

_

� I f .. � c:= r-l --_." Drivc:Pulley

Drive. _____ _ "" .-

Mandrel. ______ • __ •

Chuck. _______ ____ --�

Track. ____ •• ____ ---

Skate Whed ___ _ _

Carriage___ _ _ ____ � .J!.

Frame _________ ._

. _ . __ Chuck

_. __ Track

____ , ... Oil Pan

_ _ ___ .. Barrel Vise

___ ._Ca�riage

BORE· REAM· LAP

Rimn, Rod. " , Tucle .• � ... � ......

Chuck •. ��

Skate Whed

Pinion Gear ,,:�, :. Handle Pull , ' ,�

Carria,e�"

Handle "

"",

--

Pi�at Bolt

" Platrorm

Ballc\Vis�

..... " . StOp Collar , .... ,,'

. lode.ingHead ...... ,,/:. Inde. Pin

<: .... '""� Mount

RIFLER

SetScrews

Cam 83.r Piyot

CarnBar

Skate Wheel AdJu�tment

stop collar for ��h end which will keep the small pipe from fore-and-aft driftlIlg. Bolt the outer pipe firmly on the plat­fonn to line up with the rifling axle and rod. .

Cut the smaller pipe,. which is your barrel vise, enough longer than the outer plpe so that you cau have room for opposed set screws which will hold the gun barrel. Insert the small pipe into the larger and drill a small hole through both pipes; this is your first basic index refer­ence. Whh these holes firmly aligned (by a temporary pin), affix the stop collars. To index the barrel vise, space the circumference of the vise into the number of divisions (grooves) you may want to cut. You can set up a 12-groove index with just one outer index hole, and with it cut 12, 6, 4, 3 or 2 equally spaced grooves. But you must drillS additional outer indices to cut 5, 10,7. 8, 9 and II grooves. Ends of the barrel vise should be drilled and tapped at right angles for two sets of set screws each to grip the gun barrel.

Barrel Boring, Reaming First step is the oil pan. OJl a wooden template, 7' x 8" x

2", clamp the sheet metal over it, and bend the oil pan into shape. A drain hole for the cutting oil is cut through a lower corner of the pan. Solder a cup under this hole, with its own exit hole below, to hold some loose packing as a filter for the oil. For gravity feed you need a catch pan, and a reservoir mounted above the machine. An oil line connects the reser­voir to the hollow driveshaft so cutting oil will be fed to the work. Mount the oil pan with self-threading screws, through neoprene washers, into the oil pan platfonn.

Boring Head Thread one end of the driveshaft to take a chuck that

will hold the boring rod. True and polish the outer end of the driveshaft to take the pressure-snug oil line. Install the shaft in the 10" pulley and through the mou· nted thrust bearings. The boring track should be as long as the

Rifling rods and cutter head. Fore and aJt, carriage guides. Rifle barr;1

is damped In IILre wllh machine screws. Cutler in top center oj hell ,

woodtn shim In pillce below.

Rifling carriage. Fore and aft, guide rails. Right, wooden operating handle. Background, cam bar. Center, bicycle sprocht is actuated by bicycle chain mounted on bar which slides in channel iron as carriage move.I. Note ball bearing skate wheels (bearings) in moun/so Rifling rod at left ctnter.

longest barrel you will bore plus length of the longest bit or reamer you will use, fastened firmly through Ihe bot­tom of the oil pan to Ihe oil pan plalform.

The boring barrel vise is made from a 2 � thickwall pipe, with opposed set screws to grip the barrel. This vise is firmly mounted to the carriage, which can be made of either wood or metal. Depending on the scrap available, make guides that will force the carriage to slide accurately down the track. Criteria for mating of the carriage and track is that they be an easy sliding fit, free of wobble, so the cutter won't chatter. Centerline of the vise must cor­respond to centerline of the drive chuck.

One end of the hollow boring rod is held in the chuck. The other end is brazed or threaded 10 the cuUer, with a bleed hole through the rod wall at the cutter so cutting oil can reach the work, exit the tube and be caught in the oil pan.

Lapping, Choking The device for rechoking, internal polishing, bore lap­

ping and removing rust from barrel chambers is mounted paraUed to the boring tool, and nearer the operator since

. the carriage is hand-fed. Begin with 'the track. a simple strip of hardwood 7'

long, 2· wide and 1.1 It deep, nailed to its platform. The wooden carriage must be wide enough to handle the wid­est double barrel guns and drillings with which you will work. as well as single barrels and barrels having awk­ward integral lumps or mounts. The carriage cover is clamped to its base with four opposed wing nut machine bolts, so when the cover is screwed down tightly on a bar­rel. the barrel is firmly held in the carriage. The carriage moves on ball bearing roUer skate wheels to allow eas)'. consistent carriage movement alan, its track_

Mount the ball bearing mandrel so the shaft aligns with the track. If barrel-widths of the guns you are working

with is extreme, instead of nailing the track to its plat­form, you will have to provide lateral adjustment. On lhe outer driving end of the mandrel put a 6" drive pulley then a 2" pulley that will transfer power \0 Ihe cutting de: vice. The inside end of the mandrel takes the chuck. A 17S0-RPM motor, with the pulleys specified. will give proper speeds for most operations. The malar should be al least !tS: h.p., and a full I h.p. wi\\ be less likely to stall and leave a cutter stuck ill a high-priced shotgun tube.

OH Seals Culling oil is gravity fed to the boring drive shaft by a cop­

per oil line, bent to shape so it exerts pressurc against the end oflhe hollow mandrel. The two pa�sages arc mated against a hollow neoprene "button" (which you can shape with a little experiment), and the oil itself provides ample locallubrica· lion as the mandrel turns against it.

To seal the joint wherc cutting oil lcavcs the mandrel and passes through the centerless chuck to the hollow boring rod, a simple, flat, flexible neoprene or plastic washer inside the chuck prevents escape of the oil. Hold the boring rod tightly againsl this washer while locking the chuck.

Rifling The main essentials in rifling are these: (a) make sure

the gun barrel cannot slip in the barrel vise; (b) double check before starting to make sure the bore is reamed to land, not groove, diameter; (c) keep a sharp cutter, with enough relief not to bind; (d) never stop the cutter during a stroke; (e) never change the relationship of the rifler to the bore until the job is completed.

To rifle. mount the barrel, muzzle toward the carriage. flfTDly between the set screws. Slip the rifling rod through the barrel and mount it in the chuck. AffIX the cutler head and adjust the shims for the first cut, which should be very light, .0001· or Jess. Lock. the indexing head. Anchor the cam bar

Son, Gerald, Jr. operates rifttr. Below, center, carriage of boring/ rramlng machinr In oil pan. Extrrme below, Shotgun barrels In carrlolt of shotgun tool.

3" Pulley On Motor

-----10" ---. --

DRIVE

. 6" Pulley

/

on the spacing bar for the required amount of twist. The cut is made on a pull stroke. Make the fITs! cut with a

dry bore. After the cut, inspect the bore to make sure the cut is clean and consistent. Now remove the shims from the cut­ter head, put a patch wet wilh cuning oil on the head bulton, and push the head through the bore in reverse, thus cleaning out the chip and lubricating for Ihe next cut.

Shim up the cutter for about a .003· cut (thickness of a brown paper bag). Pu\l the indexing pin, rolate the barrel vise to the next hole, and replace the pin. Squirt more cut­ting oil in the bore and take a new cut. When you have been all the way around the index, add anothcr paper shim and repeat until the desired depth of groove is cut. About .012�isusual.

Choke Cutting To remove choke, or to cut a recess choke in a cylinder

bore barrel, lock an ordinary brake cylinder hone, avail­able from most auto supply houses, in the shotgun chuck. Lubricate with cutting oil. When cutting recess choke, provide carriage stops so the cutter will cut only the length of choke you want. Don't slop the carriage in niid­track; hep a steady back-and-forth motion. Stop the motor and remove the barrel frequently for inspection.

Lapping, Internal Polishing As diagrammed, the power shaft of this tool turns at

approximately 800 RPM, ideal for most such work. At this speed it exerts a lot of bulldog power - enough to wrench the carriage out of your hands if it gets away from you, possibly severely injuring you. It is wise 10 pro­'vide a foot or knee cutoff switch so you can instantly stop the motor if necessary. Faster speeds build up too much heat and burnish rather than cut; slower speeds tend t� gal! and may freeze the cutter in the work.

The chuck on the driveshaft should be large enough to hold up to Vz" cutter rods. You will need Yz /I down to 1/4" rods to cover JO down to .410 bore tubes, each a little longer than the longest gun barrel to be worked on. The end of each rod should be slit with a hacksaw or mill for 4" to I " depth depending on rod dianleter, to accept part of a sheet of emery doth. Coarse grits are best; flne grits may polish a bit prettier, but have been found not to have enough friction to control shot well.

You will also need some rubber to shim up the emery as the cut proceeds and wears the grit down. Use plenty of cutting oil.

In practice, tear off a piece of emery cloth, slip it into the slit of the rod, and wind it so it will follow the direc­tion of rotation. Use as much winding as you can force into the bore as the rod begins rotating. In full-length bore polishing, keep the carriage moving full-length back and forth, with no stopping, and with considerable pres­sure being needed to hold the carriage and to make it move back and forth. When the resistance becomes easy, slide the carriage off the cutter, stop the motor, and add shimming or more emery; fe-lube and cut again.

Never let the emery stop in the tube or it may stick and give you fits removing it without damage. To help pre­vent such a catastrophe, keep drive belts and chuck very tight, and use a motor you can't stall.

Doring, Reaming The e.�selltia1s of these operations are to have al\ ade­

quate flow of cutting oil; to make sure the cutting rod doesn't slip in the chuck; and to have the carriage free of all undue wobble that would cause the cutter to chatter.

Boring is best done on a pull stroke, because the entire hollow rod aets as a pilot, and the emire bore behind the

In my rlzht hand, chuck j<'hlch holdJ bo,;n,l"gm(n, rods; 01 lIS le!t, cult/n, oft/ttd lint, In It/t hllnd, chuck which holds shottun lapp'''' rod, Nou wooden slide at lowtr 't/I, /0 adjusl b,'t /tns/on, Top, rift' tnurtl�ls"

Anolh" vi .... of shOlg"n barr" vise!carriag' (fronl); rear, barin,!

reaming chuck.

bil is available 10 take the chips. Keep the bit going and the carriage moving or your stopping will show up as a ripple in thc bore.

Reaming is usually done immediately after the boring, and can be done on either a pull or a push stroke. 1n the instant machine, sct up for boring on a pull stroke, ream­ing should bc done likewise. The weight-pulley-cable ap­Dlication will result in much smoothcr reaming than is ,)Ossible by hand.

An dfective rcamer can be made by grinding down a wornou! square file of applicable site, which automati­cally provides a feeding taper and a soft iron end to braze to the rod. It should be ground so that the first cut is very shallow. For succecding cuts, place a long wooden shim between one side of it and thc bore, so the shim will force the opposite cutting corner to ream. Add paper shims as necessary. as in rining.

Excellcnt reamers also can be made of lathe tool bilS, particularly cobalt or tungsten carbide bils. In silver sol­dering or brazing the bits to the rods, use as little heat as possible and a heat sink, to prevent drawing the temper. Use the automatic gravity oiler if at all possible, and plenty of cutting oil. .

'A lengthy volume could be written on the techniques o'f rifling, choking, boring, reaming, lapping and the other potentials of this maching. You will enjoy lurnin.g these things as you operate your Own homemade machine.

Construction Procedure: The main frame must be built first. Joinls musl be

bolted and glued to prevent looseness from working vi­brations. Flooring over the bottom is optional, but pro­vides a place for accessories. Solid boards must be used for the rifling mechanism and the lapping bed. A mid­levelshelfmwt be provided for the molor, its height de­ltndent upon size of the molor and length of the belu (a

minimum of 1 h.p. motor, because you don', want a lap

to get stuck midway of a bore, which might ruin the whole job). Above the motor pulley, a sliding mount must be provided for the lapping arbor and pulley· and behind it, a mandrell on which to mount the chuck and puUey for the boring and reaming device.

After installation of the above, a track must be made on which the cradle for the lapped (bore polished barrel) will run. Recommended size is 2 V2" by Y2 II depth to whatever length barrel you expect to process. The cradle, running on four rolter skate wheels, is made of oak, with a cover to hold the barrel, of the same material. The cover is clamped by four wingnut bolts to hold the barrel tight when being lapped or polished as it is passed to and fro for application of the rod which is held in the chuck.

Behind the lapping· polishing track is the part for bor­ing and reaming. A sheet metal pan is mounted here, with neoprene washers so it won't leak the cutting oil which is fed in through the chuck holding the reamer or drill. This oil is fed from a I-gallon can mounted head-high above the far end of the machine, as a gravity feed. The oil flows down through the chuck into the hollow rod to which the drill Of reamer is attached, and escapes through a hole drilled in the rod just behind the cutler. A drain hole is provided for the pan. ::

The rifling device could be made separate from the rest of the machine, but is mounted atop it for practical working usc. The whole thing is mounted on a 2 x 6 board, pivoted at the far end Vvith a bolt so it can be swung to the left to give more room for working it. Guide rails (of whatever material is

available) are attached to either edge, so the rifling index will move in a straight line. A block of wood is made so it has flanges which follow the guide rails. To this is bolted a half­square steel beam, which serves as a channel for the index chain to run back and forth. The chain, fastened solid at both ends, is a common bicycle chain. This chain actuates a com­mon bicycle sprocket (from the same scrap bike, in this case) which is fastened to a chuck which holds the rifling cutter rod. The sprocket is mounted in pillow blocks, so it can tum as the head is slid back and forth. The progression of the tum (pitch) is regulated by a cam bar. The bar is anchored at the near end of the guide rails, the far end being able to swing in and out depending on the rifling pitch desired. The far right end of the chain mount has a bracket which s lides along the eam bar, so that as the rig is pulled (this is a pull CUller), the eam makes the chain move right or left which, in tum, re­volves the sprocket, that tums the culler rod.

The barrel vise is a hollow steel tube also mounted on the same board; it has four big headed set screws to hold the barrel firm for rifling. This tube goes inside the index tube. The index tube is pre-indexed with 6 holes (more if you want more than 6 turns to the length). You put a steel pin through the index into a matching hole in the barrel vise; make a pass with the cutter; pull the pin, rotate the vise until the pin drops into the next hole; then make an­ot�er pa�s with

_ the cutter, and so on.

In �ifling, after you cfamp the barrel in the vise, you damp the cuUer rod in the chuck, run it through the bar­rel so it comes out the far side, screw the cutter head to it and crosspin the cutter so it won't unscrew. Put a shim (common brown paper is about .003 "') under the elev�,tor, squirt culting oil in the bore, and pull one pass. Rem'ove the shim, push the rod back through the bore, rotate the barrel one hole, and rcpeat. When you have finished all 6 grooves (or however many you wish to index), add an­other thickness of papcr (or whatever) under the first shim, and repeat the cutting process. Usually this is done four times, for a groove depth of .Oll". Push a tight patch through the finished rined bore; if it is too rough, lap it smooth with a poured lead slug and valve grinding compound, or a grit of your choice.

To operate the lapping/polishing device, clamp the gun barrel fllTTLiy in the carriage, so the bore lines up with the rod held in the chuck. Hold the carriagejirmly ..... ith both hands or the torque may take it away from you and make a grand mess. To leave both hands free, it is best to install a motor s""itt;:h that you can kill with a motion o£ your knee. A Vz W diameter longer than the gun barrel should be ha.cksawed­sptit about thIee inches at the working end to accept a wind­in& of emery cloth. A more slender rod may whip and be dangerous - even fatal -- as it revolves without a center rest. The emery cloth should be wound to follow the direction of the turning rod. It should be as tight as you can comfortably control; a backing of a piece of bicycle inner tube will pro­vide the fit and also allow nexibility. Cutting oil should be squirted into the bore and onto the emery cloth, and the emery slowly fitted to start into the bore. With hand pres­sure, the cloth is passed back and forth slowly through the bore. A finer grit should be used 10 finish the job. Never Jet the turning rod stop with the emery doth in the bore.

In using the drilling device, or the reamer, also do not let the culler stop in the bore. The drill or reamer is pro-

Detail of all comer joints. Frame is of finished 2x4's, which of course actually measure j 0 It, Longitudinal members are through boiled to upright Unon; cross members extend across tenon and upright and are lot screwed into logitudinal member. All joints, before final takeup of the bolts and screws, are glued with eXlerlor Weldwood glue, available in small amounts/rom almost any hardware store or craft shop. All other wooden connections are simple lap joints secured with double through bolts and glue. No'!e of the dimensions aTe critical. They may be varied, depending upon materials a�'ailabJe to whomever is constructing the machine.

pelled by a gravity weight, through a pulley; if it balks add a bit of propulsion by hand but never force it rapidly: Barrel Machine--Materials required Frame 56 lineal feet 4· x 4" lumber (mllin frame); 28 lineal feet 2" x 2" lumber (secondary frame); 24 lineal feet 2" x 6" lumber (main platforms); 19 square feet of flooring; 4 square feel of 2" material (for motor mount); I pint glue; machine bolts, or lagscrews, with washers, to pin joints.

Rifling Rig Track Platform - wood 8' x 2" x 10" (included in frame above); Tracks - preferably steel, two 5 ' sections of channel iron (old garage door hanger tracks will do).

Jpde�ng Head Indexing sleeve - iron pipe 6" to 12" long, 2 II! " 10; Stop collars - 2" sections of above piece of pipe; Stop collar set screws - 1 pair setscrews in each collar; Induing sleeve mount-wood, l' x 4" x 4"; Barrel vise - iron pipe longer than sleeve, 2 !Ii" 00; Barrel vise lock screws - two sets of fOur opposed machine screws; Indexing stop - sma!! tapered eel p in to match index holes.

Pitcb Inuex Cam bar - iron, 54" x I Y:" x 'fa"; Cam bar pivot - short' 9" section cut from same stock, plus bolt; Spacing bar -iron, 42", cuI from same stock; Spacing bar pivot - bolt, through bar inlO platform.

RifiiD&Head Rifling rod(s) - slightly under bore size(s); Riflins rod chuck - simple lap CUI joint plus steel sleeve Jock; Rifling rod cutter * steel rod, length and diameter to suit; Rifling cutter - 1,1 "x III " piece of old file, lathe bit, elc.

Carriage Carriage b lock - wood, 12" x 6" x 2"; Carriage grips - wood, 20" x 3" X I"; Thrust bearings - two ball bearing roller skate wheels; Bearings mounts -bent iron straps, bolted down; Rack gear - bicycle chain securely screwed to rack gear bar; Rack gear bar - iron, 42" x 1 Yz" x Y4 1/; Carn roller bar - 8" section of same stock; Carn roller bolts - short bolts to fasten skate wheels to carn bar; Rack gear bar guide - channel iron, slip fit for bar; Pinion geai - rear sprocket from bicy­cle, matched to chain; Pinion gear shaft - shaft through pinion and bear­ings, 6" long.

Boring - Reaming Power pulley - standard V, 10� di­ameter, !IS II bore; Drive belt - stan­dard V to match, 40 II length; Shaft­hollow seamless steel tube !IS NOD, 12" long; Bearings - matches pair standard mounted ball bearings, YIII bore; Oil tank - I, 3, or 5 gallon can (for cutting oil); Oil feeder line -standard t/8" copper tubing 36" long, with cock; Oil seal - neoprene or vinyl button between shaft and line; Oil pan - strip of galvanized roofing (flashing) 96" x 12 "; Oil sump - small tin cup, plus filter ma­terial; Track - inverted channel iron 60" x 2"; Track bolts - four anchor bolts hold track to bed.

Carriage Barrel vise - iron pipe 24" x 2" ID, plus lock machine screws; Carriage block - wood, 18" x 2 VI" xl"; Car­riage guide - iron straps, screwed to block

-; Boring bars - hollow steel,

length and diameter to suit; Cutters _ bits, reamers to suit, machine or handmade; Chuck - stout 3-jaw, centerless, to accept th" slock; Oil seal- neoprene or vinyl washer to fit inside chuck against heel.

Lapping - Choking Power pulley - standard V, 6", with VI: " bore; Transmission pulley - stan­dard V, 2", Vi" bore; Main drive belt· standard V, 44"; Bearing unit -standard ball bearing mandrel, DE V2 " shaft; Chuck - cheap hand· tight

3-jaw to take VI" stock; Track - wood, 84" x 2" x II:! "; Carriage - two wooden boards 16 If x 4 "; clamp bolts to grip barrel between boards, 4 skate wheels; Carriage stops - wooden pegs, spaced in track as work requires; Lapping rod - steel, maximum diameter to suit bore and job; Cutters - wound emery cloth, abrasive coated felt bobs, or automo­tive brake cylinder hone.

Power . Motor - heavy duty 3/. or 1 h.p., 220

volts, 1750 RPM preferred; Motor pulley - standard V. 3 ,. diameter, to fit motor shaft; Motor mount - wood (in­cluded in frame materials); Motor switch - foot or knee switch, for emer­gency cutoff.

Miscellaneous Cutting oil - at least 1 gallon; Do not use lubricating oil to cut; Hardware -assortment of bolts. Jag screws, rna· chine screws as needed; Paint - vinyl,

epoxy or polyeurethane enamel will help keep machine easy to clean, and will protect against oil rot; Solder - for oil pan and sump. •

\100.,) ;"" ".��i,,� Ih. -0'1'''1' f"r r;rIi,,� II ... �"" 1.:0".1, \,,10' Ih., )(,,;.1.- ,," II". b.,,,,·I,. "·hid"II,,.II'j(h rl,,' m"k_ n".r • • "r�,;.", .. f ,h.< ",,((,·r.),a. ". ,I .. , ., .. 1,11.· i_ 1'"II,oJ ,,1""1='

L f. Kuehn, obcve, rifling 0 muule.loodu, borrel with equipment and tool. of hi. Own de.ign ond monu/oClu'e; righ', onorher .iew �I 'he home'mode rifling equipmen'. Skill olld pu'ie"ce 'If. e 'equired on atloching 'he wooden .plin". '0 'he cylinde •. It '�qu"e • • r"am· ing ond bending rhin .triPI 01 o,h ond ollaching wi,h ,crew •.

At top, above, two views of rifling heads. Under the sc ale is a wedge for adjust­Ing the cutters; second from the bottom Is a float used for clearing the barrel of the old rifling; at bottom is an adjust­ing device. Right, close-up view of the head of the rifling guide, the index boards and their method of attachment.

Uniform TwIst Rllllng

Study the diagram on lhe lefl. Jfyou want to make a rifling cyUnder that has one tum In 36�. you can start with a cylinder that Is 36� long where lhe grooves are to be cut. A flex­Ible metal wire Is attached to one end of the wooden cylinder at poInt \. It Is then stretched Slln.Jght away from the cylinder to a point that Is equal to the circumference {dIstance around lhe cylinder!. polm 2. From point 2 the WIre Is stretched to it poInt (3) toward. the other end of tile cylinder mat 1$ e.nctly 36� from point 1. It Is best If the cyUnder Is lying flat on a table or workbench. Point 2 should be stapled or

lacked to lhe �nch so tilal It do<::s nOI move. Now roll the cylinder toward poInt 2. As the cyllnder Is rolled. the wIre from pOUlt I ·2 Will roll around one end of the cylinder. When you have finished rolling the cylinder POints I an(t 2 �I,ollid come together Now the wire from pOint 2 . 3 make one spiral arou.nd the cylll1der 1[1 tl,e 36" length.

· DEEP HOLE DRILLS Lei us wlk 1.I 1iltlc <Jhcml the Deep HIlle Drill. Sizes. and thl' Grimling of the orill. What <-I Deep Hole Drill look like. and "111111.' of the terminology of Ihe rarhitlc drill.

I will nUl g(1 inlt) thcgrimJing ttl much of the Deep 1-1t)1t; Bils. as m{l�1 will buy lhe sizes that they need. When you have III huy the 'V' luhe. amI. Ihclirililips, plus insHllIlhc tlrilillrivcr, iJnd tip. il isjll�1 a"uul as cheap to huy the completed drill. Ifyuu want tll griml your tlrililips. the various makers if Glrhidc lools will he able tll supply ynu wilh Ihe scvcrotl �izcs (If Carhide deep helle drill tips Ihal you \\ill ncell. The gnuJc()f t.:;lrhidc u!-.ua IlyslIp* plied ror deep hole lip:>. is IIK1.

GRINDING TIPS Tu set up for grinding the deep hole tips. all Ihal is necessary is 10 turn 2 short pieces of drill rod, ahoul I inch long, center one end of

Deep Hole Drill Tips each piece, The drill rod shuuld be the same size as the drill tip that you are planning to grind. Gel a small V way, or'a piece of

finish angle. Lay the tip and the 2 pieces of drill rod, with the cenlers out lO c�l:h end of tile lip. Get some low melting silvcrs()ldcr and j()in the 3 picces.

• and C

D

I E

IIVEl

AS DEG.

0

I'OEG.

_. -

FLU

20 DEG.

0

20DEG.

PosnON CHISLE

D PRIMARY CLEARANCE POINT AT

, / 'A' I .19JXDIA.

-1- I

SECON??

J--\� �::SS

CLEARANCE THAN ,020

i--. L---..

DRILL TIP CLEARANCE

Usc Ihe lowesl name possihlc 10 melt I he silver solder, as 10 much heat will or Gin (;ra(;k Ihe GHhillc lip. Whcn donc lei (001 in the fixture. When cool set up hetwccn centers of the lathe. set tail stock over so

AUTOMATICALLY,.. g�����o o��e' FIXTURE

NO"'r.NCL .. Tunr or cuN ...... ,

you will have <J I lkgrcc indudcu taper per inch rrom the front or (ulling edge or t i p to t he hark.

After this. grind the primary land. This will have to he ground to ahsolutcrcntl'r. AJkr 1 his is done. hcaL Ihedrill t ip lip and remove the

{ S-) I I

DRILL TUBING OjCUTIl�G EDGE C--::=========:::; � . �-f;----- -�� - 1 - ;

HOLE )' DRILL liP THROGH TIP

DRILL TIP Be TUBE

ceOiered ends. Grind lhe remainingsilvcr solder from lhe carbidc lip. iflheholc>are plugged, drill lhcm oul. I have found lhal welders chalk rubbed inlO Ihe holes of Ihe l ip will help 10 keep the solder from plugging il . The drill can now be moun led 10 the drill lubing.

ORILL TIP MAKES IT'S OWNCENTEft

The V luhing can he purchase from High Sianoun!. or Donjon. address arc in the hack of the hook under suppliers. 1 would rCl.:llffi­mend Ihal Y()U huy Ihe firsl ()Jie from Ihe suppliers. This will save you some head aches on your first harre!. The urill will last for several humlrcd harrcls if you have no m.:dtlcn(, ami you take (arc of them.

DRILLING THE RIFLE BARREL In Ihi.; dmp't'rwc \\· i l l cm'(:r I h e pron: ...... uf makin),! lhl' I i l ll: 11;1 1 ' 1: 1 . 13y III IW you kIll 1\\ III 1\\ 1 hI..' 1< II)h : l l l' l"t 'II'" fueled. and ha\'t' " h:. ... u· ilka of hnw the ri l le har l c! j ... lIIadc. I \\ i l l nnw ll'll you "h:p 11\ "'\'P hl l\\' 10 go "hOlll rnakill,!.! 01 J ilk h;mel.

Firs! I would S I:1 I 1 \\ j I ll :1 t r IX iurh x 2(, inch IIltl.!! ]licu.: 01 p:;;n tiT q fl\"Sprnnf. Thi ... <,Iccl WI II dri l l . 1""::1111 . ., nll riflc h(', 1 1 I 1 i l l l l . :IIHI ;,111I11�1 IICl(,1' .I!.iw, allY " ! l l l h k . Thv nrq Illill!! In th. i ... In ] 1 1 1 1 1 1 1 i ... I > : 1 I i l 1 llH: 1:" l ll .. Ian: 1111 01 1l' .:nd. and (cnlel d ri l l i t . On Ihl' , . , h , ' , l"lld i . h bl:sl In lact" i. n i l :thl '

r.,·jakcsl l I v I hal I l i e ' , ' nd I hal Y' HI 1 1.:111('1 d I i l led h 1 1 : 1 1 : 1 1 1 0 1" 1 1 1 1" I I II AII!.!f I I H' 1I:l I l d h l:,n'd I . 1 1 . k:lvc i l l':-;ll'ndl'll. Irtl J l l l hl: clwd; : 1 1 ' 1 ' 1 1 1 (, im hc'i.

If , Ill' hand i"' ."1 i{'k i Illl I I (1111 I hl' cnd ( lr I hl' 1<11 lie. 111:1 kl a wllar. \\ il h 4 SCi Sl'rl·\\' ..... �n lilt' hanl'l clIl he l'l'!Hl'ICUHIlU I i,!!id. Al lhl' l1ieh ... pccll 1 11;1 1 I iiI..' 11;1 I 1 t'l r... til i l led. I he end ni l he harTl'1 wil l ... 1 : 1 1 1 1 1 1 r1l1l 1 1 1 1 1 and vihr;I1t.'.

The rhip box i ... in',Jalled w i r l l r he s rarh:r hll"ihill!! ill pla(,l', ;11111 rhe slarlel' hll:-.hill� i ... H'I .�· ( " ;udully nusIil'u lIJl H!!ainSI I lll' h:l l i d hlank.

(:Ol1I1CCI :111 1 lie shields, UIIII'I I"I IrL!CI :thOUl l ht: C lIH' Pll lhc: t'nd nr ,hc l.l lhe Ihal will rCll1 l l1 l ilt: Clil whel; you ,!!o IIHOII!!,h th(' haHt'1 \\'jlll the

lIrill. 8011 ihe III i 1 l 1lrivcI holder.ccntering it wil h Ihe renter I I I the lail stuck. 11 would he 111111(' ftl'l:llr<lIC if II would he dnll<' \\Oh a ... han

dlUdccJ ill till: III.!ad �tuLk, t hrough the opening that hullis the drill drivJ.:f,

Sct lhl: lle(;p lit Ill' drill ill Ihe drill drivl!r (11 11)(.: I:ilrriage, l:(mnel:l the hylll allli,· huse In I Ill! l i l l illg. NIIW \,t,;ry c.·iHcfully �Iafl I he drill I ip illio the �Iailci hll!-lhing. IkItH'c.· yllil 1111"11 1111 Ihe I li l lll Il!sl II (1 I I l , lIllUhlc dl�d Ihe !-let �Llew� that hilids Ille drill ill, IfYlll l lurn 1I11 1hc oil ilIHI

SJo:T SCJU:WS .'OK C�Nl t:JtINQ 8.-\KkU.

lATHE WITII COLLETS FOR 1I0LDlNG BARREl,

turn II p rI ll: P 1"(;."'.'" " r..:, Y� It, wi l l hh IW O l l r 1 1 11.: d I i l l il ild I '� \ ........ ihk chip I hl: l ip, <lml i,ho g..:1 all i l i l hi l i l l

Turn UII I I I ..: oil . hUI bdl lre yc III ti l ) l lwk..: �II I" : Ihal l ile vidvl' is ()P�I\ al l I he way..,t1 I l lere i" J I l l pll ':"'�11 rc i I I I he I i II":. I I cwryl hi ng i� U K you ,He pumping I hL' oil h.II.:" 1 l 1 1he lank, wit l i very l i l l lc oil glling t h rough Ihe drill . N, IW dll�c tile valve �l( )wly. watching t lie pn; .... �urL' (Ill the ,!.:'ilIge. when i l geb lip I I I ()oo I I I liJIJ 111 ..... . which is ahout I he righl pressure fur 3D calihtr h'IHeb.

Lei il run for ,I JJl illllle ()j' �o It H:her" h II' leak .... l .utI" ami �l'C IHI\\' much oil i:-. cllming OUI {II I Ill: l ip. Theh� �l1ollld he qui lL' a hi t . Thb i .... iI1lPlll l ; I I I I .. � wlh·lI yt) I I ;l I c d l i l l i llg l h i:-. I. ... OIiC wily t h a t ylli l watdl to sec i t your dl i l l b plllggL·tl Up. ;\lIy l i llll: I he nllw slow:-. 111 1\\,11, I I I �ttlP�. or pn':","'lIfc goe .... II p . ..,h II 1 (jOWl! Illc kcd fa"' l . Ill' you wi 1 / l uin I he dril l . I will ,IS:-'lIl11e t l lat Y' II I have :t l h'"dv I'llilllgl'll l l lc quirk ('!lange gcarssil

you clIn get a slower feetl. A gootl ,�I<lrl ing poinl woultl he .OO{)X feetl per reviliul iOIl.

PRESSURE AND VISCOSITY

MATERIAL . 1 56 .250 .5fHI

LOW VIS. - I'.S.1. 100 - HOO 100 - HOO 125 - 700

ALLOY

IIIGII VIS. - 1'.S.1. 1 fI0 - HOO 1 00 - HOO 125 - Hon

ALLOY

I 1 1 G I I VIS. - I'.S.I. 10f) - HOO 100 - HOO 1 25 - Hilil

SI'to:t.;t)

300 VIS - I'.S.I. 1fI0 - HOO

STAINIJo;SS

Now ifyuu lire reatly. have all thc s h icltls up. no leaks. turn Dn Ihe lalhe. Bcfme you tlo t h is make sure Ihal Ihe tlrill lip is no\ tllut:hing the h<Jfn:1. The lathc !'hllUld he funning ahnu t 4000 rpm. hul you GHI run it a t jts rl:gul<Jrspcctl. It will take longer hH.lrill the harrel. and the drill might tcnll lowlInlier a l i t l leon the slower RPM. Nowwilh the oil on, feed the drill ililO the harrd hlank very slowly hy hand. The dril l and tubing will prob.bly challer. Unless the drill tube starts io buckle, keep reeding it in. an<.l after i l goes jn 1/8 in or so it will Slt)P chattering.

Once it SlOpS chaltering engage the reed. It should start drilling with no chatter. I wouh.l recommend thai you keep your hand lin thetlri l l IUhing ror two re.sons; ( I ) - Jryour hand is o n Ihe luhingyou will he able to nil what is going 011 i n the harre!. There is a t.:ertain rill to the tubing when the drill is culling right. (2) Your hand will act as a vibration damper ror the lIrili.

Rememher lu keel' your hand on Ihe drill all the lime to reel Ihe

vihralio,,'s on Ihe drill. Aner " short while you will he able 10 lell cxacUy how Ihe drill is (Ioing. Aner a few harrels you will he ahle 10 lell when Ihe drill is uull, Of it gels (hipped. Under normal c.;omJitions the drill should he sharpened ahout every two barrels. To sharpen i t is only necessary to just touch the t:utting surf<Jl:c wilh the silicon caroil!c (green wheel), or diamoml wheel, ralhcnhan grimlingtlll i l ic

surfaces.

SPEEDS AND FEEDS

MATEIUAL 'I'll .250 TO .SIHI TO .750

LOW IU'M 6700 4.l1l0 2 1 1HI

ALLOY 1 . 1'.11. .IHHI.1 .IHII .IHII

I I I G I I IU'M .1400 Will 1511(1

ALLOY 1 . 1' . 11 . .001 .0111 .IHII

I I IG I I IU'M 2910 ZIOII I HIMI

SPEEIJ 1 . 1'.11. .1111114 .IIOO� .1I(HI5

JOII I(I'M J4011 ZIOII I HIMI

STAI N LESS 1 . 1'.11. .11110.\ .IHHI.\ .1HH14

41HI0 IU'M .l4tHl 2 100 IHIHI

STAIN U.:SS 1.1'.11 .11110] .IHHI.1 .IHH14

The angles on [h� face of the lIrill is fa irly l:ritit:al, as [hey will change. There m�y hcSp(l[S ruhhing thcllrill hccause lack (lfdcarance, may cut t:urvcd holes. or m<ly [urn oul rihhon t.:hips. These prohlcms can he usual ly he traccli ID an improperly sharpcm:ll dril l. You shouldn't have �ny rrouh1c on the l1rilling if you have followcl1 inst ructions. By now you will have pn)hahly 1H1Iicell Ihat as the pressure (lfthc ()it goes, so docs the temperature.

On .... mall c.:a/ihcrs the Llril 1 tUhing get rcal warm. This is IltJrJmtl. By nowVlIu should hC<lhout till thcwCty through the harrel. When thcdrill com��s through lhe end of the harrel. your now o f oil in Ihe rh ip hox will SlOp ahrupt ly. Open the valve on the hypass line ttl dmp Ihe oil pressure. Let the drill travel aho u l ltno lhcr 1/4 inrh allLl Llisengagc lhe rccd lcveranll hack nut the drill. when it all the wayout ShUL C\,crything t.1uwn.

Well you have done it. You have drilled your rirsl harrel. The rest should he cCisy now. /l' e\'erything WetS Llone right the harrel should he perfectly s lr:Jighl. Leave I he harrel i n the lathe as the 1 1f.:xt operation will he reaming the lIrillc(j harrel.

THE DEEP HOLE DRILLING LATHE

CONVERTING THE LATHE

You will nced a lathe with a hole through the hcalJ �I\ld: 01 al least I 114 inch . Thi� is so you can l<ike the 2(l inch or Itln!.!cr halTl'i hlank Ihrou£h thc spimllc. You wil l :1I�o Ilced to gel a ,l!carl rain"o )IIU Gill rcUUf.:c till: Ic.:.cll \lr l lle lalhl..' lIuwl1 l o a l ll:aSI .OO{)� It'l'lI PCI Il:\nhllinn.

THIS SLOW FEED IS NECESSARY TO BE ,181.1: TO IJRII.I. THE 1 7 CAL. BARRELS. FRUM TIlE I lelL BARREl.S TIlE FEED WILL BE SPEEDED UP AS THE CAL. GETS BIGGER.

Alsu ifylIu have rliln� It) make lluilC a few tI;'lrn..'ls it wtlUlLI he wise It) gCl lhe right size pullc)'!'. ltl he utile Hl inl:rc<l!;c thl..' spcctJ \lrlhc�pinc.lh.! up lu 3000 RPM. Now you might say. <lnu some or the people who manufacture Ihe hearings for Ihe \alhe. lh"l lhe hearings wi\\ ntll l"kc this kiml of spccll.

My drilling !tuhe was a 10 illl:h Clausing. 36 im:h hcl1, whidl I usclJ X-9 hours aday. Sumetimes 7 d<lYs a week for almost 5 YCCJrs hchHl: I had lo change the bearings.

The Key 10 this is (;OOD 011. AND PLENlY OF IT. There is little pressure on the bearings when drilling or reaming. just a light push or pull on Ihe spindle.

Also if you ha\'e plans 10 make quite a few harrels using cut rining. it would he wise 10 gel Ihe righl Sil£ pulleys 10 he ahle 10 increase the speed of Ihe spindle up 10 2(XX) RPM to handle the smaller calibers such as 30 caliber. My drilling lathe for reboring was a older South Bend wilh a 60 inch hcd . which I used H·9 hOllrs a day. This lalhe was excellent for rehuring and liner making. and proved excellent for cut rining. Somelimes 7 days a week for aimosl 5 years before I had to change the bearings.

STARTER BUSHING CHIP BOX

BARREL DRILL

LATHE CHUCK

DRILLING SETUP

If your lathe doesn't have an oil tray or chip pan underneath, you will have to construct one. The tray needs 10 extend a few inches past the head stock spindle. If it does not it won't be to much of a problem to huild a cover thai will faslen III the lalhe or lray 10 caldt l ile llil from Ihcbarrcl anti return il lo the tray. This cover needs to he high enough 10cOvcrthespindie hole with a piece of canvas with a hllic in II III keep Ihe oil from splallering all over everything.

COOLANT VOLUME REQUI R EMENTS

VOLUME

DEI'TH OF HOLE

6" 1 2" 1 8" 29" 36"

HOLE nIA.

INCHES

3/1 6 - 1/4" 2 3 3 3 3

5/1 6 - 1 /8" 4 4 5 66 6

1 5/32 - 1/2" 5 6 8 1 0 "

1 7/32 - 3/4" 7 8 1 0 1 3 1 7

CHUCK COVER You will need a t:IlVCt thaI will gu liver the J jaw chut:k. or (1I11CI, as there will hC4uilc a hil ofuiJ Ihnlwn 'Iul lhcrc. Thbcl)\'crt:an hemadc w raiscstraighl up emu 1m the tn,n! there should he a long \Iu' h. dcar thctlrill ur rC<lmer luhc. Y[IU will alsu need an uit \,;untaincr •• tl al 1c<lM 55 gallon!'>. This c<ln he the oil drum thaI the oil !.:LImes in.

Thcrcwillalsu ncell 10 Ilea (unlilincrtJI al lea!>! 2u �;,II'J/t_, h! �';ttt:h the oil and t:hips herllrC il reI urns \0 lhe m"inIJilt:.mIHiul'r. Y" lI wil] need some kim.! ul O<lrnCS whirh (an he I im:h angle inll1 I"iu 11;11 in lhc lray in Ihe J'!lhc. Thb. i� to help )'cl'iHalc [hc (hips frum Ille uil. "nd help III settle lhc fine (hips. From there il goes 10 iI I 1/2 iudl return pipe un lhc lr<.ly. down [0 ahoul iJ foot off lhe nullom ul lht: 211 galJun cCJntaincr. This is Ut'J1C III hClpscparate the chips InUll Ihct.iI. From this cunlaincr the oil over now.� through a I 1/4 inch pipe 10 thc 55 gall"n urum, which i� laying un Ih �illc.

In rrunl urlhcovcrllow pipe is a lar!!c magnci which wlil lrap lhcvcry finc melal Thai lliull'\ have limc In scille. This will prolong lhl." life "f yuur pump.

HYDRAULIC PUMP

Yuu will ncell a hydwuli( pump that wili lurn lIut iI\ \c,I\' 54�l l�!lf rrc.�urc. and a gtxKl now ralc. You will nced the hi,!!h IHC\�UrC rur drilling to gCl lhc rcquircu now 10 rt'movc the chips. In thl' rC;lming operation. you wil l also ncctl il large volume nfuil ill kl�l'P the nutes dear. Nol cnuugh oil now anu the I1UIC� of Ihe Il'amcr 11111.1 1 uin the reamer and hiHn:1.

COOLANT VISCOSITY

Conlanl viscl)sily ftnllrillsi1.t� 1/4 tll.VXinch�htIUld hcX!)/115 Sayl'lc,1t Secunds al UK) degrees.

PUI a barrel blank i n Ihe lalhe Ihal has theendsquared and trued, press Ihe unhardened Slaner bushing into Ihe bearing. Then very carefully move Ihe chip box wilh Ihe slarter bushing and bearing up flush with Ihe end of the harTel. Make sure that the hushing is Oush with the barrel, and not canted. Tighten down the chip hox, turn on the machine to makesurc all is running true. Ifeverythingis running true, set in the deep hole drill the size you are making Ihe hushing for, turn on the uil. SCI for low pressure. The drill point will just be Slaned in the hushing.

Turn on the lathe, and slowly feed the drill tip into the hushing, and into Ihc h,lrrcl forii dcplh tlfaht)ul a 1/4 inch. Rack(JUI when lhistlcplh is reached, shut off the oil, and (urn off the machine. This method can he used ira (orren size reamer cannot he ohtaincd. This mClhno will not give you the dosesl fit, hul if start ing the drill very carefully will almost always give you a straight hole.

BUSHING (HEAT TREATING)

After the hand is drillt:c..I to size iI can he stamped for size, amI heal treated. Bring up the temperature in the furnace ttl proper lempcrd. lun:. UI:Jllhl.! nushingwilh II CtlmpuuntJ [hal willsHJp Scaling,and put in the furnace. .I have used a surface hardening compound for this purpt)sc wilhcxcdlcnl results. Hardand Tuffisvcry gOixl. AsStlilfl as Ihchushing has rCl.lchcd the proper temperature. rcmOVC llnd qllcnl'il in it gmxl 4ucnchingoil. You will not nced 10 draw the \cmpcron [he hushing ilS we need all lhe lliInJncss we l<ln get.

Th;shushingwi!l lasl rur a many l'tarrds, anuwhcn ilslan, !OWC<.Lr, you will kllt)w as YIIU will start h) gel cHluked urr ccnlCr hl)Ic..�.

Uimensions for the starter nushin� I lule

CuliitCl' U"iII Uiametcl'

1 72 . 1 64

224 .2 1 2

244 .2ZX

257 .244 Dlmen.loDs for the 2M .2511 Stareer Bu.blng 2711 .2M

284 .2711

.lOX .2Y3

.�().� .2Y7

32.� .304 3]8 322 350 34.� 375 3(�1 44 .4 1 5 457 .443

DEEP HOLE DRILLING

Normally in ltnytlccp hulctlrillingllpcratiun, the h:.rrcJ turn .. , IIntJ Ihe urill isstalinnary. The rCaStlO riiT IhisL"an he secn in. YIIU will notice thai with Ihcsinglc lipg.undrill lha\ ilunlyculsun nncctlgc. A, il tlrills in thcbarrcl it only cuts nn unccugt.:..and as it drill� it drills in Ihe !'Ilmel ils makes ils llwn ,-"Cnler. Duc \ulhe high RPM urlhe h:.rrcl, it makes its own (cnler as il drills. This is Ihe rcasun why an ;u.:l.:oralc !Harler hushing is so impunanl.

Thc tlritling Ilfa rilk harrel is actually thcsimptcsi und mlIS\ trlluh!e frecuperaLion orall. When Ihc drill is nut Maned waigh! iI will try 10 pick up the center IJf rulatiun. and the hlile is lme !clOg L"urvc.

We nurmally turned out IOUur murc mmplclctJ rille I'IlIrrcls pcrwcek. and in lhe tlrilling upcralion we L'Ould use lowskill help. Ali lhal was

________ .

n.

"'.

CS5a.

ry was for Ihe uperalurs was In SCI up Ihe ma..:hine. lurn it on.

They had 10 walch so Ihe drill wouldn'l plug up with chips, shul il off when done, and Ihen reload it and slarl again. When you gel everylhing sel up righl. you will be able to turn oul 3-4 compleled barrels a day with no problem on ONE lalhe. This is a compleled harrel lhal is drilled. reamed and rilled.

Now aboul lhe laSl lhing lhal will be needed is a special Sleady Rc&t 1O SUPPO�I lhe drill lubing as il drills. This will help Loul down tile vlhrauons thai will some times start in the tlrill.

-----------------------

You CAN NOT allow these vihrations to slart. If it uocs it l:an l:::.use the carhide drill tip III chip. and if you do not catch it in time it can also cause the drill to plug up and twiSi the t ipoff. Will give you a good idea ofwhal " Deep Hole Drill looks like.

I want to point out Ih::'l this drilling setup is not limilcd lo just barrels. It ("'3n he uscll for 4uitc a hit df other imJuslriul opcral ions. where extremely accurate holes arc neeued. Also with carhide drill tips. very hard sleel can he drilled. For odd shaped items whereyuu are unohle

PRESSURE AND VISCOSITY

MATEIUAL .156 .250 .500

LOW VIS. - I'.S.1. IIH. - HlHl 100 - 800 125 - 7lN'

ALI.OY

1111; II VIS. - 1'.S.1. 1110 - 8lH. 100 - 8lN. 125 - IMHI AI.LOY

111(;11 VIS. - I'.S.I. 1 110 - 800 11". - 8lH. 125 - IMH'

SI'I':":1l

:!IN. VIS - I'.S.I. I OO - 8lH'

STAIN I.I'�"S

10 rOlale the drill. you can set up the operation where the drill can lie

rotatcd using special tooling.

PRESSURE AND VISCOSITY CHART.

Thcscwill givc)'uu thc prc.�sureand Visl;osily ("fYl/urOH Cuolarll for dilferent Iypes of materials. Do nut furget It) put the shield liver the end uf the harrel, so when you tlr[ll lhruugh Ihe harrcl the nil will nul he sprayed uver the enlire shup.

TOOL F O R G U N S M I T H S - A N D O T H ERS

W. o . MEEK oullincs an old mClhod of drilling barrels

.Host readers are familiar with D-bits, which are used as substitutes

for reamers in many model workshops, alld hare been referred to in several }'1E constructional articles. But recent qlleries suggest that the D-bit is not as well known as it should be, e ven to professional engineers. This article describes one of the first and most important applications of D-bits in deep drilling and boring operations.

Oee tube! solder to bit

t�� - -n_c _J�:-E- hl -l} <",II" .... Oil h"� S",""

,1 _

WHILE the D·bit is primarily

a gunsmith's 1001. it could be very usefu l to model

and general engineers if its method were more generally known. It is often confused with the nat bil for opening out cored holes in iron castings.

When guns were firsl int roduced. the nalUm1 peoplc to build them were the armourers and sword-l1l;lkcrs. They had developed a high standard of skill in smith's work. but they did not lise the lathe to any extent. II was found possible to make serviceable gun­barrels by hammer-welding bundles of wrought iron wires and h ... isling them at the same time. When the barrels were finish filed. they had a bernlliful grain, running in spirals like a wire rope. They were morc resistant to bursting than an ordinary bnr.

At first the bore was rormed by forging on a mandrel. By 1 600, good quality bores were produced which must have been drilled . The gUll drill, as we know it. has the advantage of being able to drill a hole accurately without the need for an accurate bed. The drill bit itself is the accurate part. Of course, modern deep�hole drills are highly accurate, multi-s.pindle, motor­driven, high�speed machUlcs-but they

, M�RCH 1962

are still the linear descendants of these old devices.

Before Hitler alter�d th,e s.ccncry. there was a quaner In B mllllll!ham where many one�lllan businesses l11adc gun pans. There I saw and sketched a deep-hole gun dril l reputed to have been made in the 1 8105. The b\.'d. a bout 10 ft long. \\ as said to have been chipped, filed :\nd scraped by hand.

There \\-as a headstock. \\ hieh had a hollow mandrel. a tailstock. with a hollow spindle. and a carriage \\ i th a screw feed and a drill holder mounted on the saddle. Connected to the drill holder was a tele�copic brass lUbe running to a high-pressure oil pump. which drew irs oil from the chip pan. through a filter. \Vhale oils were traditionally used, but cutting oils are also suitable .

The barrel [Q be drilled was swung between hollow centres, with large cones in each end. The drill was fed through a bush in the tailstock spindle, which acted as a guide bush as it was a good sliding fil.

To the bit proper, which was about four inches long, was soldered a

length or D-scction tubc. Thc pump forced oil at several hundred pounds pressure through the lube and the oi l hole in the bit. Such a force was enough to wash away the chips.

The point of the bit was made out-Dr-centre, usually about fivc­eighths or the radius of the hole. It was, of course. cut only on one side. The tube was flexible enough to allow the drill to find its own centrc. 1f it was ground right (there was a mystique about the grinding) it would produce <I perrect ly straight hole. The speed would be about 800 to 1 ,000 r.p.m .

and the feed about half . a thou a revolution.

Once started, the drill was not stopped until the hole was finished; the operator cou ld tell, by placing his finger on the drill tube and feel ing the vibrations, and by examining the swarf, how tbe drill was cutting. Correctly, it would come away in a crinkled ribbon: not in curls, as these would tend to jam up the hole.

Of course, that was not thc end: the final beautiful finish of the bore was obtained by spill boring, another old method now hardly used. [!)