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071-312-3025 (SL1) - Maintain an M60 Machine Gun

Standards: 1. Disassembled the M60 machine gun into the following groups: stock; buffer and operating rod; bolt assembly; trigger mechanism; barrel; feed cover, feed tray, and hanger; forearm; and receiver. 2. Cleaned the M60 machine gun, removed powder fouling and other foreign material and identified any unserviceable parts. Did not get CLP in the gas cylinder. 3. Lubricated the M60 machine gun. 4. Assembled the M60 machine gun, performed a function check, ensured the forearm group was locked in place, the hinge pin was interlocked with the latch engaging the sear pin, and the stock group latch engaged.

Conditions: Given an M60 machine gun that needs to be cleaned and inspected. You have a cleaning kit, cleaner lubricant preservative (CLP), lubricating oil arctic weather (LAW), swabs, a dummy cartridge, and a field table or ground cloth on which to work.

Standards:

1. Disassembled the M60 machine gun into the following groups: stock; buffer and operating rod; bolt assembly; trigger mechanism; barrel; feed cover, feed tray, and hanger; forearm; and receiver.

2. Cleaned the M60 machine gun, removed powder fouling and other foreign material and identified any unserviceable parts. Did not get CLP in the gas cylinder.

3. Lubricated the M60 machine gun.

4. Assembled the M60 machine gun, performed a function check, ensured the forearm group was locked in place, the hinge pin was interlocked with the latch engaging the sear pin, and the stock group latch engaged.

Performance Steps

WARNING: Weapon must be clear before disassembling.

1.   Clear the M60 machine gun.

a. Pull the cocking handle to the rear.

b. Lock the bolt to the rear.

c. Raise the feed cover.

d. Ensure the chamber is empty.

e. Close the feed cover.

f.  Place the safety lever on FIRE.

g. Pull the cocking handle to the rear and hold it.

h. Pull the trigger and allow the bolt to ease forward.

i.   Place the selector lever on SAFE.

2.   Remove the stock group.

a. Raise the hinged shoulder rest.

b. Insert the nose of a dummy cartridge into the latch hole (figure 071-312-3025-1).


Figure 071-312-3025-1. Stock

 

c. Push the latch down.

d. Pull the stock group to the rear, removing it from the M60 machine gun.

3.   Remove the buffer, operating rod, and bolt assembly group.

a. Remove the buffer.

(1)  Press the exposed buffer lightly with the palm of the hand (figure 071-312-3025-2).


Figure 071-312-3025-2. Buffer yoke

(2)  Remove the buffer yoke from the top of the receiver.

(3)  Remove the buffer slowly by pulling it rearward. Allow the driver spring guide to expand until the end of the guide is showing at the rear of the receiver.

(4)  Pull the buffer plunger from the driver spring guide (figure 071-312-3025‑3).


Figure 071-312-3025-3. Buffer

 

(5)  Pull the driver spring guide and spring from the receiver.

(6)  Separate the driver spring from the driver spring guide.

b. Remove the operating rod and bolt.

(1)  Grasp the pistol grip with the left hand.

(2)  Pull the cocking handle to the rear with your right hand until the bolt separates from the barrel socket.

(3)  Return the cocking handle to the forward position.

(4)  Pull the cam roller until it stops. This pulls the rod and bolt to the rear.

(5)  Push the bolt to the rear with your finger on the face of the bolt (figure 071-312-3025-4).


Figure 071-312-3025-4. Cam roller  

 

(6)  Grasp the operating rod and bolt when they are about 4 inches out of the cylinder to prevent the bolt from rotating.

(7)  Pull the operating rod and bolt from the receiver (figure 071-312-3025-5).


Figure 071-312-3025-5. Operating rod and bolt

 

(8)  Relax your grip, allowing the bolt to rotate slowly.

(9)  Grasp the bolt and operating rod with both hands. The bolt should be on the bottom, facing away from your body.

(10) Disengage the bolt from the operating rod by pulling forward on the operating handle and lifting upward (figure 071-312-3025-6).


Figure 071-312-3025-6. Bolt assembly and operating rod being separated

 

4.   Remove the trigger mechanism group consisting of the grip, leaf spring, and retaining pin.

a. Press in on the rear of the leaf spring.

b. Rotate the rear of the leaf spring up to clear it from the sear pin (figure 071-312-3025-7).


Figure 071-312-3025-7. Sear pin

 

c. Pull the leaf spring to the rear, disengaging it from the front notch of the retaining pin.

d. Remove the retaining pin by pushing it to the left.

e. Remove the trigger mechanism.

(1)  Slide the trigger mechanism slightly forward.

(2)  Rotate the front of the trigger mechanism housing down.

(3)  Remove the trigger mechanism (figure 071-312-3025-8).


Figure 071-312-3025-8. Trigger mechanism group

 

5.   Remove the cover, feed tray, and hanger group.

a. Remove the feed cover.

(1)  Raise the feed cover.

(2)  Unlock the hinge pin using a pointed object (figure 071-312-3025-9).


Figure 071-312-3025-9. Hinge pin latch

 

(3)  Push the hinge pin out of its recess and remove it from the opposite side of the hinge pin latch.

(4)  Lift the feed cover from the receiver assembly.

(5)  Remove the feed cover spring from the cover.

b. Lift the feed tray and hanger group from the receiver assembly (figure 071-312-3025-10).


Figure 071-312-3025-10. Feed tray and hanger group

 

6.   Remove the barrel group, made up of the barrel, flash suppressor, front sight, bipod assembly, and gas cylinder system.

a. Push in on the barrel locking lever plunger (figure 071-312-3025-11).


Figure 071-312-3025-11. Barrel locking lever

 

b. Raise the barrel locking lever to the vertical position.

c. Remove the barrel group by pulling it straight to the front of the rifle.

7.   Remove the forearm assembly.

a. Turn the receiver so the top is facing down.

b. Insert a pointed object into the latch hole at the bottom rear of the forearm assembly (figure 071-312-3025-12).


Figure 071-312-3025-12. Forearm latch

 

c. Release the forearm latch by pressing downward with a pointed object.

d. Raise the rear of the forearm assembly slightly.

e. Pull the forearm assembly to the front to remove it.

Note. This completes general disassembly of the M60 machine gun. The receiver group requires no disassembly.

8.   Clean the M60 machine gun.

CAUTION: Do not use gasoline, kerosene, benzene, or high pressure water, steam, or air for cleaning.

a. Position the gas cylinder above the barrel during cleaning so as not to get CLP in the gas cylinder.

b. Clean the bore using CLP and a bore brush attached to a cleaning rod.

(1)  Run the brush through the bore without reversing the direction of the brush while it is in the bore.

(2)  Repeat the preceding step until most of the powder fouling and other foreign matter have been removed.

(3)  Swab out the bore several times using a cleaning rod and a swab wet with CLP.

(4)  Swab out the bore several times using a cleaning rod and a dry swab.

c. Clean the chamber using CLP and a chamber brush attached to a cleaning rod.

(1)  Run the brush through the chamber.

(2)  Repeat the preceding step until most of the powder fouling and other foreign matter have been removed.

(3)  Swab out the chamber several times using a cleaning rod and a swab wet with CLP.

(4)  Swab out the chamber several times using a cleaning rod and dry swab.

d. Clean the receiver with a receiver brush and CLP.

(1)  Brush the receiver until most of the powder fouling and other foreign matter have been removed.

(2)  Swab out the receiver several times using a cleaning rod and a swab wet with CLP.

(3)  Swab out the receiver several times using a cleaning rod and dry swab.

e. Clean the buffer and operating rod group using CLP and a receiver brush. Do not submerge the buffer in any cleaning solvents.

(1)  Brush the buffer group until powder fouling and other foreign matter have been removed.

(2)  Swab out the operating rod several times using a cleaning rod and a swab wet with CLP.

(3)  Swab out the operating rod several times using a cleaning rod and a dry swab.

f.  Wipe down all parts of the M60 machine gun except the rubber-coated parts with a rag wet with CLP.

g. Dry all parts cleaned with CLP.

9.   Inspect the parts for serviceability.

a. Stock group.

(1)  Ensure the stock group fits securely on the receiver.

(2)  Check the guide rails for cracks, bends, or burrs.

(3)  Check the shoulder rest and stock latch for binding.

(4)  Check the rubber coating for gumming or cracking.

b. Buffer and operating rod group.

(1)  Check the yoke and yoke recess for burrs, cracks, or bends.

(2)  Ensure the buffer plunger fits easily into the recess in the driver spring guide.

(3)  Check the driver spring for kinks and broken or separated wires.

(4)  Check the driver spring guide for bends, ensuring the spool is tight on the shaft.

(5)  Check the sear notch on the operating rod for excessive wear or burring.

c. Bolt assembly group.

(1)  Check the bolt plug, bolt plug pin, and actuator cam assembly for chips and burrs.

(2)  Check the firing pin for cracks or wear on the tip.

(3)  Check the ejector and extractor to ensure they are under spring tension and are not chipped or worn.

d. Trigger mechanism group.

(1)  Check the shoulder of the sear for excessive wear.

(2)  Check the mechanism for cracks (check carefully near the retaining pins).

(3)  Check the leaf spring to ensure it is under tension.

(4)  Check the safety for correct function. (The sear should move only slightly when the safety lever is on SAFE, and freely when the safety lever is on FIRE.)

e. Barrel group.

(1)  Check to ensure the suppressor is tight.

(2)  Check the front sight and barrel locking-cam for bends, cracks, burrs, or excessive wear.

(3)  Check the bipod assembly for correct functioning. (The legs should lock in the up and down position. The leg extension should lock at the desired heights.)

(4)  Check the gas piston and gas cylinder for burrs.

(5)  Check the detent on the tab lock washers of the gas cylinder nut and gas cylinder extension to ensure it is not broken.

(6)  Check the bleeder hole in the gas cylinder extension to ensure it is clear.

f.  Feed cover, feed tray, and hanger.

(1)  Check to ensure all parts inside the feed cover are under spring tension.

(2)  Check the feed cover to ensure it is not bent or torn.

(3)  Check the belt holding pawl to ensure it is under spring tension.

g. Forearm assembly.

(1)  Check the assembly to ensure it is not bent.

(2)  Check the spring in the latch to ensure it is not broken.

h. Receiver group.

(1)  Check the receiver to ensure it is not bent or cracked.

(2)  Check the cocking handle to ensure it slides freely within its guide path.

(3)  Check the elevation scale on the rear sight to ensure it is legible. The elevation screw should not be burred or worn.

10. Lubricate the M60 machine gun.

Note. When lubricating the M60 machine gun at temperatures below 0 degrees Fahrenheit, use LAW and lubricate lightly to avoid freeze-ups; under all other conditions, use CLP. When using LAW, lubrication techniques are the same as for CLP.

a. Make sure you do not get CLP inside the buffer assembly or inside the gas cylinder.

b. Run a cleaning patch with several drops of CLP on it through the bore.

c. Wipe down all non-rubber-coated exterior surfaces of the M60 machine gun with a rag with several drops of CLP on it.

d. Use CLP to lubricate the following surfaces.

(1)  Bolt locking lugs by the camming surfaces.

(2)  Operating rod surfaces along the receiver rails.

(3)  Actuator roller on the bolt and where the bolt actuator rides the feed pawl carrier on the underside of the cover assembly.

11. Assemble the M60 machine gun in the following order.

a. Assemble the forearm group.

(1)  Guide the forearm assembly over the operating rod tube, ensuring the operating rod does not strike the baffles inside the forearm assembly.

(2)  Align the recess in the forearm assembly with the end of the operating rod tube.

(3)  Tap up on the bottom rear of the forearm assembly with the palm of your hand to lock it in position.

b. Assemble the feed cover, feed tray, and hanger group.

(1)  Align the guides of the feed tray and hanger on the left side of the cover mounting brackets and sear, the feed tray, and hanger in the receiver.

(2)  Replace the cover.

(a)   Insert the cover spring in the cover.

(b)   Align the cover with the mounting brackets.

(c)   Insert the hinge pin from the right side.

(d)   Insert the hinge pin latch from the left side, making sure that the hinge pin and the hinge pin latch interlock.

c. Assemble the barrel group.

(1)  Make sure the barrel locking lever is in the vertical position (figure 071-312-3025-11).

(2)  Put the rear of the barrel through the forearm assembly.

(3)  Align the gas cylinder nut with its recess in the forearm assembly.

(4)  Lower the barrel locking lever to its most downward position.

d. Assemble the trigger mechanism group (figure 071-312-3025-8).

(1)  Engage the holding notch of the trigger mechanism group in its recess in the bottom of the receiver (figure 071-312-3025-8).

(2)  Rotate the front of the trigger mechanism up.

(3)  Align the holes of the trigger mechanism with the mounting bracket on the receiver.

(4)  Insert the retaining pin from the left.

(5)  Attach the leaf spring by placing the open end of the leaf spring on the retaining pin.

(6)  Engage the hooked end to the sear pin.

e. Assemble the bolt and operating rod group.

(1)  Hold the bolt securely in one hand with the camming slot up. The face of the bolt should be toward the body.

(2)  Position the rear of the operating rod yoke against the rear firing pin spool with the other hand (figure 071-312-3025-13).


Figure 071-312-3025-13. Rear of operating rod yoke positioned against rear firing pin spool

 

(3)  Push on operating rod, compressing the firing pin spring.

(4)  Position the operating rod yoke between the firing pin spool.

(5)  Push forward on the rear of the bolt with the other hand, causing the bolt to rotate until the locking lugs are vertical and the cam roller is up.

(6)  Push the operating rod and bolt (ensure the cam roller faces up) into the receiver until the end of the operating rod is even with the rear of the receiver (figure 071-312-3025-14).


Figure 071-312-3025-14. Operating rod and bolt

 

(7)  Put the driver spring guide into the driver spring.

(8)  Put the free end of the driver spring in the opening of the operating rod.

(9)  Pull the trigger.

(10) Push in the driver spring until the head of the guide is about one inch from the receiver (figure 071-312-3025-3).

f.  Assemble the buffer group (figure 071-312-3025-3).

(1)  Put the buffer plunger into the driver spring guide.

(2)  Push forward on the buffer until the operating rod and bolt go fully forward.

(3)  Push in on the buffer until the recesses on the buffer are aligned with the recesses in the receiver.

(4)  Place the buffer yoke in the buffer recess on top of the receiver.

g. Assemble the stock group.

(1)  Align the guide rails of the stock group with the guide rails on the receiver.

(2)  Push forward until the stock is fully seated. You will hear a distinct click when the latch engages.

12. Perform a function check to ensure that the M60 machine gun is assembled correctly.

a. Place the safety on FIRE.

b. Pull the cocking handle to the rear.

c. Return the cocking handle forward to the locked position.

d. Close the cover.

e. Place the safety on SAFE.

f.  Pull the trigger; the weapon should not fire.

g. Place the safety on FIRE.

h. Pull the cocking handle to the rear, holding it in that position.

i.   Pull the trigger, allowing the bolt to ease forward.

j.   Store the weapon in the arms room or continue the mission.

Evaluation Preparation: 

Setup: At the test site, provide one M60 machine gun, all required cleaning equipment, and a field table or ground cloth to work on.

Brief Soldier: Tell the soldier to disassemble, clean, assemble, and perform a function check on the machine gun.

Performance Measures

GO

NO GO

1.   Cleared the weapon so the selector lever was on SAFE.

--

--

2.   Disassembled the weapon into the major groups without damaging any components.

--

--

3.   Cleaned the weapon, removed the powder fouling and other foreign material and dried all components cleaned with CLP.

--

--

4.   Identified any damaged, worn, or malfunctioning components.

--

--

5.   Assembled the weapon in the correct sequence without damaging any components.

--

--

6.   Performed a function check, ensured the weapon operated properly.

--

--

Evaluation Guidance:  Score the soldier GO if all performance measures are passed. Score the soldier NO GO if any performance measure is failed. If the soldier scores NO GO, show him what was done wrong and how to do it correctly.

References

 

Required

Related

 

FM 3-22.68

 

 

TM 9-1005-224-10

 

 

TM 9-1005-224-23&P