9mm Machine Gun Fiaring

A chipped/broken Extractor Claw (3), weak Extractor Spring (2) or impeded Extractor (1) can cause a weapon stoppage, more commonly referred to as a failure to extract malfunction. Check Firing Pin (4) for straightness and make sure the Tip (5) is completely rounded. Check Feed Roller (6) for spring tension when compressed. Check Firing Pin Spring (7) for kinks, breaks and retention capability. Inspect for pits on bolt face. Make sure that Firing Pin Hole (8) is round and not elongated.

Cracked or weak Extractor spring.

Firing Pin bent or round tip, spring is weak, kinked or broken. Excessive pitting on face of bolt and/or elongated firing pin hole.

Firing Pin The M249

Check for bulges on the top of slide assembly by placing a straight edge (such as a six inch steel rule) on the top and sighting across. If light is detected between the top of the slide assembly and the straight edge, a bulge exits.

Bulged.

Check for bulges on the top of slide assembly by placing a straight edge (such as a six inch steel rule) on the top and sighting across. If light is detected between the top of the slide assembly and the straight edge, a bulge exits.

M249 Sear Pin

BULGE

BAD CONDITION

GOOD CONDITION

BULGE

BAD CONDITION

GOOD CONDITION

Item No.

Inter -val

Man-Hour

Item To Be Checked or Serviced

Procedure

Not Fully Mission Capable If:

8.

Piston Assembly

Inspect Piston Rod (1) for bends, breaks, burrs, or cracks. Inspect Tower Portion (2) and Tube Portion (3) for looseness. Inspect Hole (4) for cracks.

NOTE

Looseness between Tower Portion (2) and Tube Portion (3) can cause sluggish operation and contribute to malfunctions.

^ 1jDU013

Bent, broken, burred or cracked. Tube portion loose.

9.

Mechanism

Assembly

Inspect Tripping Lever (1) and Sear (2) for burrs on edges or shoulders. Push back on Tripping Lever (1) to raise Sear (2). Place Safety (3) in SAFE position (red band not visible). Pull Trigger (10), Sear (2) should not drop down far enough to lock in the downward position. Place Safety (3) in FIRE position (red band visible). Pull Trigger (10), Sear (2) should drop down and lock in the downward position. Check Grip Assembly (9) for cracks, and looseness between Pistol Grip (4) and Housing (8). Plate Assembly (5) should be present and functional. Check Sear Spring (6) to ensure the leg of spring is behind Trigger Pin (7) and not between the Trigger (10) and the Trigger Pin (7).

Trigger assembly is bent or damaged, preventing operation. Sear is excessively worn/cracked or broken.

Safety does not function properly.

Parts are missing/ broken. Springs are deformed/weak and prevent proper functioning.

Item No.

Inter -val

Man-Hour

Item To Be Checked or Serviced

Procedure

Not Fully Mission Capable If:

(Cont.)

Trigger Mechanism Assembly (Cont.)

NOTE

A bent or improperly installed Sear Spring (6) can cause the Trigger (10) to be extremely hard to pull. If this happens, the Sear (2) does not release the piston assembly and causes a weapon stoppage, more commonly referred to as a failure to fire malfunction. If the Sear Spring (6) is not bent or broken and is properly installed, but the Trigger (10) is hard to pull, the Tripping Lever (1) may be worn out.

Item No.

Inter -val

Man-Hour

Item To Be Checked or Serviced

Procedure

Not Fully Mission Capable If:

10.

Cover and Feed Mechanism Assembly (shown removed for clarity)

Move Feed Lever (1) back and forth to make sure the feed mechanism operates smoothly without binding. Push in on the two Cover Latches (2) to make sure Retaining Clip (3) is not weak or missing and the Cover Latches (2) do not bind in Cover Assembly (4). Push on two Cartridge Guides (5) and two Feed Pawls (6) to make sure the springs are not weak, missing or improperly installed. NOTE: Weak or improperly installed springs under the feed pawls can allow the bolt to underride the cartridge base and cause a weapon stoppage, more commonly referred to as a failure to feed/strip malfunction.

NOTE

Weak or improperly installed springs under the cartridge guides, can allow uncontrolled/loose rounds in the receiver mechanism during the feeding cycle and cause a weapon stoppage, more commonly referred to as a failure to chamber.

Cover latch does not hold cover closed. Parts missing, loose, or damaged. Cover components do not operate smoothly.

Item No.

Inter -val

Man-Hour

Item To Be Checked or Serviced

Procedure

Not Fully Mission Capable If:

Cover and Feed Mechanism Assembly (shown removed for clarity) (Cont.)

Ensure cover fully opens under spring tension.

Was this article helpful?

0 0

Post a comment