u.s. rifle caliber.3 0, ml fm 23-5

7/28/2019 U.S. RIFLE CALIBER.3 0, Ml FM 23-5

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FM 3-DEPARTMENT OF THE ARMY FELD MANUAL

US. RFLECALIBER30, Ml

EADQUARTERS, DEPARTMENT OF THE ARMYMAY 1965

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*FM 22-5

FIELD MANUALNo. 23-5 I

HEADQUARTERSDEPARTMENTOFTHEARMYWASHINGTON, D.C., I7 Huy 1965

U.S. RIFLE, CALIBER .30, MlP-* PWR 1. INTRODUCTION________________ _____ _ ____ ___________________ ____ _____________ I- 4 32. MECHANICALTRAINING_______,____________________________________________ 5-11 53. OPERATION AND FUNCTIONING__________ ______ __________________ _______ ___ 12-15 144. STOPPAGES AND IMMEDIATE ACTION____ __-___________ __________ _____ _____ 16-19 195. MAINTENANCE_____________________________.________________________________ 20-24 206. AMMUNITION______-__--_____________-_______-_-_______-____________---_____- 25,26 25I. REFERENCES_ ______ __________________ ____ ___ _____ ___________________________ _____ 26

*This manual supersedesFM 23-5, 26 kphmber 1956, including Cl, 22 June 1960.

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CHAPTER 1INTRODUCTION

and Scopea. This manual is a guide for commanders andthe mechanical operation of the Ml rifle. I ts a detailed description of the rifle and its

neral characteristics; procedures for disassem-y and assembly methods of loading; an ex-ation of functioning; a discussion of stop-a description of themunition and instructions on the care andning of both the weapon and ammunition.he material presented is applicable, without

b. Marksmanship training is covered in FMc. Users of this manual are encouraged to sub-ove the manual. Comments should be keyed tospecific page, paragraph, and line of the textwhich the change is recommended. Reasonsd be provided for each comment to insureCom-nts should be forwarded direct to the Com-andant, U.S. Army Infantry School, Fort Ben-

Importance of Mechanical TrainingThe rifle is the soldiers basic weapon. I t givesm an individual and powerful capability formbat. To get the most out of his individualmbat capability, the soldier must develop twoills to an equal degree: he must be able to fires weapon well enough to get hits on battlefieldgets, and he must know enough about itsing parts to keep them operating smoothlythe rifle will not fail him. The soldier gets hising skill on marksmanship training ranges and

from the mechanical training that is outlined inthis manual.3. Description of the Rifle

The U.S. rifle caliber .30, Ml, (fig. 1) is anair-cooled, gas-operated, clip-fed, and semiauto-matic shoulder weapon. This means that the aircools the barrel ; that the power to cock the rifleand chamber the succeeding round comes fromthe expanding gas of the round fired previously ;that it is loaded by inserting a metal clip (con-taining a maximum of eight rounds) into the re-ceiver ; and that the rifle fires one round each timethe trigger is pulled.4. General DataWeight :

Complete with sling, eight-round clip and cleaningequipment (approximate) _ 11% pounds.Length :Overall _____________ _____ _ 43inches.Sighta :Front _____________________ Fixed.Rear _______ _____ ____ ______ Adjustable. One clickof elevation or wind-age movea the strikeof the bullet .7 centi-meters at 26 meters.Trigger pull :Minimum _________________ 5% pounds.Maximum _________________ 7% pound&Ammunition ___________________ See chapter 6.Muzzle velocity (approximately) _ 853 metera (2,SOO eet )per second.Chamber pressure ______ ___ _____ 50,000 pounds persquare inch.Maximum range________________ 3,200 meters.Maximum effective range______ 460 meters.Maximum effective rate of flre *__ 16 to 24 rounds perminute.

Maximum effective range ia the greatest dletance at which aweapon mag be expected to 5re accurately to inflict caeualtiee ordamage.*Althou htrained ri eman can 5re 1f there is no Brescribed mnxlmum rate of fire, ato 24 aimed rounds per mnute.

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Figure 1. U.8. rifle, caliber 30, Ml.

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CHAPTER 2MECHANICAL TRAINING

5. Disassembly and Assemblya. The individual soldier is authorized to dis-assemble his rifle to the extent called f& d strip-

ping. Table I, Disassembly Authorization (para.7)) shows the parts he is permitted to disassemble.his amount of disassembly is necessary for nor-b. The rifle should be disassembled and assem-only when maintenance is required or for in-Repeated disassembly andly causes excessive wear of parts and soones them unserviceable and reduces the ac-acy of the weapon.c. The rifle has been designed so that it may beapart and put together easily. No force isded if it is disassembled and assembled cor-

ectly. The parts of one rifle, except the bolt,be interchanged with those of another whenbolta should never

d. As the rifle is disassembled, the parts shouldlaid out on a clean surface, in the order of re-

moval, from left to right. This makes assemblyeasier because the parts are assembled in the re-verse order of disassembly. The names of t.herifle parts (nomenclature) should be taught alongwith disassembly and assembly to make futureinstruction on the rifle easier to understand.6. Clearing the Rifle

The first step in handling any weapon is toclear it. I f the ri fle is loaded, unload it as de-scribed in paragraph 13. The Ml rifle is clearwhen there is no ammunition in the chamber orreceiver, the bolt is locked to the rear, and thesafety is engaged. To clear the rifle, pull theoperating rod handle all the way to the rear, in-spect the chamber and receiver to insure that norounds are present and push the safety to itslocked position (inside the trigger guard).7. Disassembly Into the Three Main Groups

a. The three main groups are the trigger hous-ing group, the barrel and receiver group, and thestock group (fig. 2).

Fi gure 2. The three m& n groupe.

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b. To disassemble the rifle into the three maingroups, first insure that the weapon is clear andthen allow the bolt to go forward by depressingthe follower with the right thumb and allowingthe bolt to ride forward over the followerassembly.

c. Place the rifle butt against the left thigh,sights to the left. With the thumb and forefingerof the right hand, pull downward and outwardon the rear of the trigger guard. Swing the trig-ger guard out as far as it will go and lift out thetrigger housing group (fig. 3).

d. To separate the barrel and receiver from thestock lay the weapon on a flat surface with thesights up, muzzle to the left. With the left hand,grasp the rear of the receiver and raise the rifle.With the right hand, give a downward blow,grasping the small of the stock. This will sep-arate the stock group from the barrel and receivergroup.8. Disassembly of the Barrel and Receiver

Groupa. Place the barrel and receiver group, with the

bolt closed, on a flat surface with the sights down(insuring that the aperture is at its lowest posi-tion), muzzle pointing to the left. Holding therear of the receiver with the right hand, grasp thefollower rod with the thumb and forefinger ofthe left hand and disengage it from the followerarm by moving it toward the muzzle (fig. 4).

Remove the follower rod and operating rod springby withdrawing them to the right. Do not sep-arate these parts.

b. Using the tip of a dummy cartridge, removethe follower arm pin by pushing it from the farside of the receiver toward the body (fig. 5).

Fi gure 9. Removing the tri gger housing group.

Table I. Disassembly AuthorizationOroups and parts Individual soldier ArUlOrer Maintenancepersonnel only

SEPARATION :INTO THREE MAI N GROUPS___----___-_______-__- X___._____.___DISASSEMBLY:BARREL AND RECE IVER GROUP ______ ______ _____ X_ __________ __Bolt assembly____________________._________________ Remove_-----__ Repair_________ Repair/Replace.Gas cylinder________-_____-_______-____-_______--___ Remove__----__ Repair___._____ Repair/Replace.Gas cylinder lock___-____--______--_________________ Remove___-____ Remove________ Repair/Replace.Clip latch______________________--_-___--___________ ________________ Repair_______-_ Repair/Replace.Rear sight_______-_____-_____________________-_____ ________________ Repair____.____ Repair/Replace.Slide from follower____________.--_____-_-_____-_-__.. ________________ ________________ Repair/Replace.Accelerator from operating rod catch assembly--__--__-_ ________________ ________________ Repair/Replace.Front sight__ ________________________--__________ ________________ ________________ Repair/Replace.TRI GGER HOUSING GROUP________.________-_____ Remove________ Repair_________ Repair/Replace.

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Fi gure 4. Removing the foll ower rod and operati ng rodspring.

Fi gure 5. Removing the foll ower ~7n Pin.c. With the left hand, grasp the bullet guide,follower arm, and the operating rod catch assem-bly, and lift them out of the receiver together(fig. 6). Separate and arrange these parts fromleft to right in the following order : follower arm,operating rod catch assembly, and bullet guide.d. Reach down into the receiver and lift out thefollower assembly.e. Turn the barrel and receiver group over sothat the sights are up, muzzle pointing away fromyou. With the left hand, raise the rear of thereceiver. With the right hand, pull the operating

rod to the rear until the rear of the handle is di-rectly under the forward edge of the windageknob. With an upward and outward movement,disengage the guide lug of the operating rodthrough its dismount notch on the receiver. Re-move the operating rod (fig. 7).

Figure 6. Removing the Bu ll et guide, fol lower arm, andoperati ng rod catch assembly.

F igur e 7. Removing the operati ng rod.

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Caution: The operating rod is bent inten-tionally so that it will not bind against theenlarged portion of the barrel. Do not attemptto straighten it.f. With the right hand, grasp the bolt by theoperating lug and slide it fully to the rear; thenslide it forward, lifting upward and outward tothe right front with a slight rotating motion toremove it.g. Using the screwdriver blade of the Ml0cleaning rod handle as shown in figure 8, unscrewand remove the gas cylinder lock screw.h. Unscrew and remove the gas cylinder lock.Loosen the gas cylinder by tapping lightly towardthe muzzle on the bayonet stud with a piece ofwood or similar soft object (fig. 9). Remove thegas cylinder, taking care not to burr or damagethe splines. Do not remoue or att empt to adjust

t he front sight.i. Remove the front handguard by sliding itforward over the muzzle. Do not att empt to re-move t he rear ha& guard.

j . The parts of the barrel and receiver groupin their order of disassembly are shown in figure10.9. Assembly of the Barrel and Receiver

Groupa. Replace the front handguard by sliding itover the muzzle and insure that it is seated in thefront band.b. Place the gas cylinder over the barrel, mak-ing sure the splines are alined with their grooves.Push the gas cylinder down as far as it will go.I f tapping is necessary, use a piece of wood on thebayonet stud. Engage the threads of the gascylinder lock with those on the barrel and screwthe lock on by hand until i t is finger tight (do not

use a tool). I f the lock is not alined with the gascylinder, do not force it, but unscrew it unti l i t isalined. Replace and tighten the gas cylinder lockscrew with the handle assembly of the Ml0 clean-ing rod.c. To replace the bolt, hold i t by the operatinglug and place the rear end of the bolt onto thebridge of the receiver. Rotate the bolt counter-clockwise as far as necessary to permit the tangof the firing pin to clear the top of the bridge ofthe receiver. Guide the left locking lug of thebolt into its groove on the left side of the receiver.

Lower the righk locking lug on its bearing sur-face and slide the bolt halfway to the rear.d. To replace the operating rod, hold the han-dle with the right hand and place the piston endinto the gas cylinder. Aline the operating rodso that the recess in the hump fits over the operat-

ing lug of the bolt. While applying pressuredownward and inward on the handle, pull the op-erating rod to the rear until the guide lug is en-gaged in its groove (fig. 11). Move the operatingrod forward until the bolt is closed.e. Turn the ,barrel and receiver group over sothat the sights are down and the muzzle is to theleft. Replace the follower assembly so that itsguide ribs fit into their grooves in the receiver.Make sure that the slide of the follower is downand that the square hole is to the rear (fig. 12).The slide will rest against the bolt.f. Replace the bullet bide so that its shouldersfit into their slots in the receiver and the hole inthe toe of the bullet guide is alined with the holesin the receiver (fig. 13).

g. With the right hand, lift up the lower partof the bullet guide slightly. With the left hand,insert the rear arm of the operating rod catch as-sembly through &he clearance cut in the side ofthe bullet guide. Make sure that the rear arm isunderneath the front stud of the clip latch whichprojects into the receiver (fig. 14). Lower thebullet guide into place. Test for correct assemblyby pressing down on the front arms of the opera%-ing rod catch assembly. I t should move and youshould be able to feel the tension of the clip latchspring.h. Replace the follower arm by passing its rearstuds through the bullet guide and inserting theminto the guide grooves on the follower (fig. 15).Allow the wings of the follower arm to rest astridethe toe of the bullet guide. Aline the holes in theoperating rod catch assembly, follower arm, andbullet guide with those in the receiver and replacethe follower arm pin from the near side.i. Insert the loose end of the operating rodspring into the operating rod. Grasp the followerrod with the left hand, making sure that its humpis toward the barrel. Pull toward the muzzle,compressing the operating rod spring, and engagethe claws of the follower rod with the front studsof the follower arm (fig. 16). You may have toraise the follower assembly to do this,

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F igur e 8. Remodlcg the gaa c@hder lock acrew.

771-952-2 9

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10. Assembly of the Three Main Groupsa. Place the barrel and receiver group on aflat surface, sights down. Pick up the stock group

. * i,*i:~, 2: tr, v.m 1) ?., I . *\p- Q *%

Figure 9. Removing the gas cylinder.

and engage the U-shaped flange of the stock fer-rule in the lower band, then lower the stock grouponto the barrel and receiver group (fig. 17).

6. Unlatch and open the trigger guard. Keep-ing the base of the trigger housing group level,place it straight down into the receiver, makingsure that the locking lugs on the trigger guardenter their recesses in the receiver (fig. 18).Place the butt of the rifle on the left thigh withthe sights to the left. Close the trigger guardand latch it by striking it with the heel of theright hand. The trigger guard is latched whilethe rifle is in this position so that the rear sightwill not be damaged.11. Test for Correct Assembly

Each time the rifle is disassembled and assem-bled it should be tested to make sure that it is puttogether properly. To do this, pull the operatingrod to its rearmost position. The bolt shouldstay open. Close the bolt and snap the safety toits locked position. Squeeze the trigger. Thehammer should not fall. Push the safety to itsunlocked position and squeeze the trigger. Thehammer should fall . This test is made to checkthe operation of the safety.

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OPERATING ROD

OPERATING RODSPRING

UPPERHANDGUARD

GAS - / CYLINDER

I

IFOLLOWERLOCK ARMSCREW

CYLINDER/GAS

CYLINDERLOCK

I IFdLLOWERFOLLOWER ARM ASSEMBLYPIN OPERATINGROD CATCH&

-ASSEMBLY

Figure 10. Parts of the barr el amd receiver group L the order of di8a88mb.@.

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F igure 13. ReQtadng the bul let guide.

F igure 11. RepZucimg he operatdng rod.

F&we 14. RepZacZng he operating r od catch aasembZg.

Figure la. RepZtadw the foZZoww wsmbZ%

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c d

F igur e 17. Replacing the stock cm the bawel andreceiver group.

Figure 18. Replacing the trigger houeing group.

Figure 16. Replacing the fol lower rod and operati ng rod8P99W

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CHAPTER 3OPERATION AND FUNCTIONING

12. loading the Riflea. Singlemum?. To load a single round, pullthe operating rod all the way to the rear. Whileholding the muzzle below the horizontal, place around in the chamber and seat it with the thumb.With a knife edge of the right hand against theoperating rod handle, force the operating rodslightly to the rear. Push down on the followerassembly with the right thumb and allow the boltto ride forward. Remove the thumb from the fol-lower assembly and release the operating rod han-dle, allowing the operating rod to go all the wayforward.

6. FuJ 2 clip. To load a full clip, hold the rifleat the balance with the left hand and pull the op-erating rod handle all the way to the rear. Placethe butt of the rifle against the thigh or on theground. With the right hand, place a full clipon top of the follower assembly. Place the thumbon the center of the top round in the clip andpress the clip straight down into the receiver un-til it catches (fig. 19). Swing the right hand upand to the right to clear the bolt in i ts forwardmovement. Note that the operating rod is not heldto the rear during loading since there is no dangerof it going forward as long as pressure is main-

Ftgure 19. Loading a run clip.14

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tained on the top round in the clip. It may benecessary to strike forward on the operating rodhandle with the heel of the righthand to fullyclose and lock the bolt.

c. Pa&fatty fdkd clip. To load a partiallyfilled clip, hold the rifle in the same manner pre-scribed for a full clip. With the operating rodall the way to the rear, place an empty clip intothe receiver. Place the first round into the clipand on the follower, to the left of the followerslide. Press the second round into the clip, ex-erting a downward, turning motion until theround snaps into place. Load the remainingrounds in the same manner (fig. 20). With theknife edge of the right hand against the operatingrod handle force the operating rod slightly to therear. Push down on the top round with the rightthumb, allowing the bolt to start the top roundforward. Remove the right hand and allow theoperating rod to go forward.13. Unloading the Rifle

a. To unload a round from the chamber, sup-port the rifle butt on the thigh or on the ground ;with the right hand grasp the operating rod han-dle and pull the operating rod slowly to the rear.At the same time, place the left hand, palm down,over the receiver to catch the round as it is ejected(fig. 21). This keeps the round from falling intothe dirt or away from your position.

b. To unload a filled or partially filled clip, un-load the round that is in the chamber as describedin a above. When the operating rod reaches itsrearmost position, hold it there. Place the palmof the left hand over the receiver and depress theclip latch with the left thumb, allowing the clipto be ejected up into the hand (fig. 22). Do notrelax the rearward pressure on the operating rodhandle until after the clip has been removed.14. loading Rounds Into a Clip

a. Insert eight rounds into the clip, holding theclip and rounds in the manner shown in figure 23.Start placing the rounds in from the lower left ofthe clip and make sure that each round is againstthe rear wall so that the inner rib of the clip en-gages the extracting groove of each round. Thetop round will then be on the right, making theclip easier for a right handed firer to load in therifle. For the same reason, clips are loaded thisway at arsenals.

6. Each time rounds are loaded into a clip, theclip should be checked for long rounds. If oneround extends beyond the others, it will be hardto load the clip into the rifle. The long roundshould be seated by removing the top round, push-ing the long round into place and then replacingthe top round. Tapping the bullet against asolid surface to seat the long round may resultin the bullet being pushed back into its cartridgecase. This may damage the bullet or break the

Fi gure 20. Loading a partiall y fl Ued dip.

F igure 81. Unl oading a round lr om the chamber.

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Fi gure W. Loading rounda i& o a clip.bullet seal which could result in changes in theballistic performance of the round.15. Functioning of. the Rifle

a. The trigger must be pulled to fire each round.When the last round is fired, the empty clip isautomatically ejected and the bolt remains to therear.6. Each time a round is loaded and fired, manyparts inside the rifle work in a given order. Thisis known as the cycle of operation. This cycle

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is similar in all small arms. A knowledge of whathappens inside the rifle during this cycle of oper-ation will help the soldier understand the causeof and remedy for various stoppages.c. The cycle of operation is broken down intoeight steps. These steps are listed below, togetherwith a brief description of what actually occursinside the rifle during each step. Assume that afull or partially filled clip has been loaded intothe rifle and that the first round has been firedand the bolt is in its rearmost position (fig. 24).(1)

(2)

(3)

(4)

(5)

Feeding. Feeding takes place. when around is moved into the path of the bolt.This is done by the follower assemblyexerting an upward pressure on the bot-tom round in the clip. The follower as-sembly is continuously forced up by thepressure of the operating rod springthrough the follower rod and followerarm (fig. 24).Charnbering. Chamber&g occurs whena round is moved into the chamber. Thistakes place as the bolt goes forward un-der pressure of the expanding operatingrod spring, picking up the top round inthe clip and driving it forward into thechamber (fig. 25). Chambering is com-plete when the extractor snaps into theextracting groove on the cartridge caseand the ejector is forced into the face ofthe bolt.Loci&g. Locking is complete when thebolt is fully closed. This prevents theloss of gas pressure until the bullet hasleft the muzzle. The bolt is locked by therear camming surface in the recess in thehump of the operating rod, forcing theoperating lug of the bolt down. This en-gages the locking lugs on the bolt withtheir recesses in the receiver (fig. 26).IG=&ng. Firing occurs when the firingpin strikes the primer. As the triggeris pulled the trigger lugs are disengagedfrom the hammer hooks and the hammeris released. The hammer moves forwardunder the pressure of the hammer springand strikes the tang of the firing pm, driv-ing the firing pin against the primer andfiring the round (fig. 27).Unlocking. Unlocking occurs after thefiring of the round. As the bullet isforced through the barrel by the expand-

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ing gas, a small portion of the gas escapesthrough the gas port into the gas cylinder,forcing the operating rod to the rear (fig.28). The camming surface inside the re-cess in the hump of the operating rodforces the operating lug of the bolt up-ward, disengaging the locking lugs fromtheir IXXAXXWn the receiver. The bolt is

(3)thus unlocked and ready to be moved tothe rear (fig. 29).E&raoting. Extracting is pulling theempty cartridge case from the chamber.The extractor, which is engaged with theextracting groove on the cartridge case,withdraws the empty case as the boltmoves to the rear (fig. 30).

F igur e 84. Po84Non of part8 when the bolt 48 n it8 rearmost positi on.

F igur e 85. Chamber& g.

Fi gure 26. Loclcing.

Fi gure 87. Fi ring.

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GAS CYLINDER-GAS PORT J

F igure 2 8. Action of the gae.F igure 89. Un locking.

EXTRACTORNCAGEDNEXTRACTORROOVEN MPTYARTFWXE CASEBOLT

7 /EMPTY CARTRIDGE CASE

(7)

(8)

Figure JO.Ejecting. Ejecting is throwing theempty case from the rifle. As the boltmoves to the rear, withdrawing the casefrom the chamber, the round is held inplace by the chamber walls. When themouth of the empty case clears the cham-ber, it is ejected up and to the right bythe expanding ejector spring and ejector.Cocking. Cocking occurs when the ham-

Extracting.mer is forced into the proper position forfiring the next round. This happens asthe bolt continues to the rear. The rearend of the bolt forces the hammer backand rides over it. The hammer is caughtby the sear if the trigger is still held tothe rear, but it is caught by the triggerlugs if trigger pressure has been released(fig. 31).

m MPTY CARTRIDGE CASEMOUTH OF EMPTYCARTRIDGE CASE

HAMMER HOOKS

CHAMBER WALLS\ L HAMMER L EJECTOR

TRIGGER LUGS

F igure 31. Ejecting and cocking.18

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CHAPTER 4STOPPAGES AND IMMEDIATE ACTION

16. Stoppagesa. A stoppage is any unintentional interruptionin the cycle of operation.b. Most stoppages occur because of dirty, worn,or broken parts, and lack of lubrication. The

rifleman must be taught to watch for these de-fects and take corrective action to eliminate thembefore they cause a stoppage. Some of the morecommon stoppages, with their usual causes andremedies, are shown in table I I (para 19). Notethat the stoppages are classified according to thesteps of the cycle of operation.17. Immediate Action

a. Immediat e acti on 2 the prompt act ion takenby t he fi rer t o reduce a stoppage. To apply im-mediats action, pull the operating rod handle allthe way to the rear with the right hand, paZmup, then release it. The right hand should be heldin the manner shown in figure 32 so it will not beinjured in the event of a hangfire. Next, aim therifle and try to fire it.

b. I f a rifleman is taught to apply immediateaction quickly and properly when his ri fle fails tofire, he will be able to reduce most stoppages(table II).18. Misfire, Hangfire, and Cookoff

a. Hang&es and misfires rarely occur. Nor-mally, the firer will instinctively apply immediateaction which in most instances reduces the stop-page even when caused by a hangfire or misfire.b. Misfires are caused by one of three factors-the firer, the weapon malfunctioning (due to ex-cessive dirt, etc.), or faulty ammunition. Whenthere has been an excessive number of misfires

caused by faulty ammunition, the lot numbershould be reported to ammunition supply person-nel for inspection and determination of disposi-tion.19. Malfunctions

A malfunction is a failure of the weapon tooperate satisfactorily. Some of the common mal-functions are discussed below.

a. The clip may jump out on the seventh round.This is usually caused by a bent follower arm orbullet guide and can be corrected by replacingthem.

b. The rifle may fire in bursts of two or threerounds. This is due to the sear being broken,

F igure 52. Applying immediate a& on.

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worn, or remaining in an open position. It can d. Operating parts which fail to move fully tobe corrected by replacing the trigger assembly. the rear (short recoil) are caused by-c. The safety may release when pressure is ap- (1) Valve leak in gas cylinder lock screw.plied to the trigger. This can be caused by -abroken safety or by the trigger stop on the safetybeing worn. It can be corrected by replacing thesafety.

(2)(3)(Valve not fullySeated.)Defective operating rod spring.Undersized piston. (Caused by the useof abrasives when cleaning the piston.)

Tabl e I I . St oppages, Their Cause8 and Remedi esBtoppagea

Failure to feed___________

Failure to chamber-___-__

Failure to lock___________

Failure to fire____________

Failure to unlock_________

Failure to extract_________

Failure to eject______--_-_Failure to cock_________-_

C!W&l I RemedyLack of lubrication of operating parta_ _ _ _ _ _ _ _ _ _Defective or worn parts______,_______________Shortrecoil_________________________________Lack of lubrication of operating parts__ _ _ _ _ _ _ _ _Dirty chamber-____________________________-Defective ammunition____________________-__Lack of lubrication of operating parta__________Dirty chamber_____________________________-Dirty locking recesses___________________..____Weak operating rod spring____________________Defective ammunition_______________________Defective firing pin__________________________Defective trigger housing group_____-_________Dirty chamber______________________________Lack of lubrication of operating par&_________Insuflicientgas______________________________Dirty chamber______________________________Dirty ammunition___________________________Broken extractor________________________-___Broken ejector or spring______________________Short recoil_________________________________Defective trigger housing group_______________Short recoil_________________________________

Clean and lubricate parts (fig. 33).Replace parts.See paragraph 19d.Clean and lubricate parts.Clean chamber.Replace ammunition.Clean and lubricate parts.Clean chamber.Clean receasea.Replace spring.Replace ammunition.Replace firing pin.Repair trigger housing group.Clean chamber.Clean and lubricate parts.Tighten gas cylinder lock screw.Clean or replace worn parts.Clean chamber.Replace ammunition.Replace extractor.Replace ejector or spring.See paragraph 19d.Repair trigger housing group.See paragraph 19d.

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CHAPTER 5MAINTENANCE

20. GeneralMaintenance includes all measures taken to keepthe rifle in operating condition. This includesnormal cleaning, inspection for defective parts, re-pair, and lubrication.

21. Cleaning Materials, lubricants, andEquipmenta. Cleanina YatemX .9.(1)

(2)

(3)(4)

BOG cleaner (cleaning compound solvent(CR) ) is used primarily for cleaning thebore; however, it may be used on all metalparts for a temporary (l-day) protectionfrom rust.Hot, soapy water or boiling water is nosubstitute for bore cleaner and wiZZonlybe uaea?w&n bore cleaner


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M3 CLEANING ROD

CHAMBERBRUSH

OILER & THONG

CLEANINGRODCASE Ml0 CLEANING ROD

Figure 34. Cleawing equipment.

GREASE CONTAINER FABRIC CASE (HOLDS:ROD CLEANING. JOINTED.W/SPACER. M-ID) SPACER

AD (FOR M-lPATCH.FOLDEDTOSERVEASSPACER OR FILLER (L To DEADEN SOUND

OILER AND THONG (W/O THONG)\HANDLE (OF ~-10 CLEANING ROD)

LEANING PATCHES INSERTED TO FILL IN SPACE. WITH CARETO PACK A MINIMUM NUMBER TO KEEP BUTT PLATE CAP CLOSED

ECTIONS OFCLEANlh IG ROD

Figure 35. Stowage oj acce88ordee ht butt stock oj Ml and M lC r4fl e.s

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ammunition now manufactured has a noncorro-sive primer which makes cleaning easier, but noless important. The primer sti ll leaves a depositthat may collect moisture and promote rust if it isnot removed. The cleaning described below willremove all deposits except metal fouling which isrelatively uncommon and is removed by mainte-nance personnel.(1) Chan&r. Remove the patch holderfrom the cleaning rod and insert twopatches about halfway through the slot.Dip the patches in bore cleaner, thenwring or squeeze the excess fluid fromthe patches. Screw the Ml0 cleaning rodtogether (less the patch holder) and in-sert it all the way into the bore. Flarethe patches out, then insert the patch

holder with the wet patches into thechamber. Push the threaded end intothe chamber until it touches the cleaningrod. Hold it there with one hand andscrew the cleaning rod and the patchholder together. Pull the patches to thechamber; at the same time turning therod clockwise. Turn the rod severaltimes, wiping the chamber thoroughly.After the chamber has been thoroughlycleaned use the chamber brush in the fol-lowing manner :(4

(6)(cl(4

Screw a section of the Ml0 cleaningrod into a threaded hole of the driverratchet.Place the brush into chamber of thebarrel.Allow the rifle bolt to close slowlyagainst the end of the driver ratchet.Using the rod section as a handle, ro-tate the driver clockwise and counter-clockwise to loosen and clean residuefrom the chamber.

(2) Bore. To clean the bore saturate thebore brush with cleaning compound sol-vent (rifle bore cleaner) and-

(4

(b)

Insert the bore brush into the cham-ber. Insert the cleaning rod into thebore and screw the brush onto the rod.Pull the brush through the bore. Re-move the brush and repeat the pro-cedure as often as required to cleanthe bore.

(c) Then use one cleaning patch dampenedwith bore cleaner in the followingmanner :

(3)

(4)

(5)(6)

(7)

(8)

1. Place the patch in the patch holderand insert it into the chamber.S. Insert the cleaning rod (less the patchholder) into the bore and screw itonto the patch holder.3. Pull the cleaning rod through thebore. Repeat this procedure usingas many patches as required untilthe patches come through the boreclean.Gm cyli nd er lock xrew wi th vaZve aa-

mnb&y . Remove carbon deposits by us-ing bore cleaner, then wipe the part andoil it lightly (do not use abrasives).Check the valve to see that it is not heldopen by particles of dirt or sand.Piston of operating rod. Remove carbonfrom the piston with bore cleaner. Takecare not to damage the piston. Oil itlightly after cleaning (do not use abra-sives) .Gas cylinder. Clean the gas cylinderwith bore cleaner and patches.Face of the bolt. Clean the face of thebolt with a patch and bore cleaner, pay-ing particular attention to its insideedges. Remove the bore cleaner with drypatches and oil the part lightly.AU other parts. Use a dry cloth to re-move all dirt or sand from other partsand exterior surfaces. Apply a light coatof oil to the metal parts and rub rawlinseed oi2 into the wooden parts. Caremust be taken to prevent linseed oil fromgetting on metal parts.Cleaning frequency. The rifle must bethoroughly cleaned no later than theevening of the day it is fired. For threeconsecutive days therafter check for evi-dence of fouling by running a clean patchthrough the bore and inspecting it. Thebore should be lightly oiled after eachinspection.

23. Normal Maintenancea. When in use, the rifle should be inspected

daily for evidence of rust and general appearance.A l ight coat of oil (PL Special) should be main-tained on all metal parts.

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(1)

(2)

b. The daily inspection should also reveal anydefects such as burred, worn, or cracked parts.Defecta should be reported to the armorer forcorrectionc. A muzzle plug should never be used on therifle. I t causes moisture to collect in the bore,which causes bore rust that is a safety hazard.o?. Obtaining the proper rear sight tension isextremely important ; without it the sight willnot hold its adjustment in elevation. During nor-mal maintenance and prior to firing, the rear sightmust be checked for correct sight tension. Theindications of improper sight tension are: eleva-tion knob extremely difficult to turn, and eleva-tion knob turns freelv without an audible click.I f the elevation knob is extremely dif-

ficult to turn, the soldier must rotate the&age knob nut (with the screw-driverportion of the Ml0 cleaning rod handle)counter&xkwise blue c2ick at a time.After each click an attempt should bemade to turn the elevation knob. Repeatthis process until the elevation knob canbe turned without extreme difficulty.In the event the elevation knob is ex-tremely loose and the rear sight aperturewill not raise, the &&age knob nut mustbe turned in a clockzlrise direction, one

click at a time, until the aperture can beraised.(3) To check for proper tension the proce-dures listed below should be followed:(a) Raise the aperture to its full height.(5) Lower the aperture two clicks.(0) Grasp the rifle with the fingers aroundthe small of the stock (fig. 36) and ex-ert downward pressure on the aperturewith the thumb of the same hand.(4) I f the aperture drops, sight tension mustbe adjusted. To do this the windageknob nut must be turned in a clockwisedirection one click at a time until the aper-ture can no longer be pushed down (fig.36). I f the proper tension cannot be ob-tained, the rifle must be turned in to the

unit armorer.24. Special Maintenance

a. Before firing the rifle, the bore and the cham-ber should be cleaned and dried. A light coat ofoil should be placed on all other metal parts ex-cept those which come in contact with ammunition.b. Before firing, rifle grease should be appliedto the parts indicated in figure 33. A smallamount of grease is taken up on the stem of thegrease container cap and is applied at each place.Rifle grease is not used in extremely cold tempera-

F i gu r e 36 . P rope r u t gh t t endon .

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tures or when the rifle is exposed to extremes ofsand and dust.c. In cold climates (temperatures below freez-ing) the rifle must be kept free of moisture andexcess oil. Moisture and excess oil on the workingparts cause them to operate sluggishly or fail com-pletely. The rifle must be disassembled and wipedwith a clean, dry cloth. Drycleaning solvent maybe used if necessary to remove oil or grease. Partsthat show signs of wear may be wiped with a patchlightly dampened with lubricating oil (LAW).It is best to keep the rifle as close as possible tooutside temperatures at all times to prevent thecollection of moisture which occurs when coldmetal comes in contact with warm air. When theri fle is brought into a warm room, it should not becleaned until it has reached room temperature.d. In hot, humid climates or if exposed to saltwater or salt-water atmosphere, the ri fle must be

inspected thoroughly each day for signs of mois-ture and rust. It should be kept lightly oiled withspecial preservative lubricating oil. Raw linseedoi l should be applied frequently to the woodenparts to prevent swelling.

e. In hot, dry climates the rifle must be cleaneddaily or more often to remove sand and/or dustfrom the bore and working parts. In sandy areas,the rifle should be kept dry. The muzzle and re-ceiver should be kept covered during sand and duststorms. Wooden parts must be kept oiled withraw lh aeed oil to prevent drying. The rifle shouldbe lightly oiled when sandy or dusty conditionsdecrease.

f. Special instructions on caring for the riflewhen it is subject to nuclear, biological, or chem-ical contamination can be found in TM 3-220 andFM 2140.

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CHAPTER 6AMMUNITION

25. GeneralThe Ml rifle fires several types of ammunition.The rifleman should be able to recognize them andknow which type is best for certain targets.

26. DescriptionThe types of ammunition are identified by theirindividual markings.a. BaU, J f$. This cartridge is used againstpersonnel and unarmored targets, and can be iden-tified by its unpainted bullet.b. Armor Piercing, Jig. This cartridge is usedagainst lightly armored vehicles, protective shel-ters, and personnel, and can be identified by itsblack bullet tip.c. Armor Piercing Incendiary, Ml4. This car-tridge is used, in place of the armor piercinground, against flammable targets. The tip of thebullet is colored with aluminum paint.d. Incendiery, iK1. This cartridge is usedagainst unarmored, flammable targets. The tipof the bullet is painted blue.

e. Tracers and M&X These cartridges are foruse in observing fire, signaling, target designation,and incendiary purposes. The tips of the bulletsare painted red for the Ml and orange for theM25.

f. Blank, iIflDO8. This cartridge is used tosimulate rifle fire. The cartridge is identifiedby having no bullet, and by a cannelure in theneck of the case which is sealed by red lacquer.

g. R+ e Grenade Cartridge, M3. This cart-ridge is used with the grenade launcher to propelgrenades. The cartridge has no bullet and themouth is crimped.

h. Dummy, iK40. This cartridge is used formarksmanship training. The cartridge case hassix longitudinal corrugations and the primer hasbeen removed.

i. Match, iK72. This cartridge, used in marks-manship competition firing, can be identified bythe word MATCH on the head stamp.

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APPENDIX IREFERENCES

FM 21-5 Military Training.FM 21-6 Technique of Mil itary Instruction.FM 21-40 Small Unit Procedures in Chemical, Biological, and Radiological (CBR) Operations.FM 23-71 Rifle Marksmanship.TM 3-220 Chemical, Biological, and Radiological (CBR) Decontamination.TM 9-1900 Ammunition, General.DA Pam 108-l Index of Army Motion Pictures, Filmstrips, Slides, and Phono-Recordings.

By Order of the Secretary of the Army:

OfficialJ . C. LAMBERT,iliajor General, United States Army,Th e Adj utant General .

HAROLD K. J OHNSON,General, United States Army,Chi ef of Sta# .

Distribution :Active Awnu:DOSPER (2) USAIB (5) Bde (3)ACSI (2) USCONARC (5) Regt/Gp/Bg ( 1)DosMHf (2) USACJDC (5) 00 (2)ACSFOR (2) USAMC (5) Bn (2)CORC (2) OS Maj Comd (5) Co/Btry (1)CNGB (5) LOG-COMD (1) USATC (5)

CRD (1) Armies (5) Br Svc Sch (1) exceptWA (1) corps (3) USAOCXS (3)CINFO (1) Div (10)TIG (1) Div Arty (1)

NG: State AG (3) ; Uni&+-same aa Active Army except allowance is two (2) copies to each unit.UBAR: Units-same as Active Army except allowance is one copy to each unit.For explanation of abbreviations used, see AR 320-50.

For sale by the Superintendent of Documents, U.S. Goverument Printing OfflceWashington, D.C., 20402 - Price 25 cents

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