Mk19 Bolt Fingers

If the rounds feed across the receiver's feed area, but are not pulled to the rear and down the face of the bolt during charging or recoil, check the components as noted in this symptom's malfunctions.

CORRECTIVE ACTION

Remove rough spots with abrasive cloth. Remove burrs with a stone.

Bolt Finger

Materials/Parts

Abrasive cloth (item 3, WP 0124 00) Lubricant (as required)

References

WP 0057 00 WP 0059 00 WP 0068 00 WP 0070 00

SYMPTOM - Continued

Rounds will not extract/eject. MALFUNCTION

Firing pin will not retract (defective firing pin, cocking lever, pin, or spring).

CORRECTIVE ACTION

With the weapon assembled, charge the weapon and place on 'S' (SAFE). Observe through the receiver whether the firing pin is protruding. If the pin is protruding with the bolt to the rear, the cocking lever, pin, or spring is defective.

FIRING PIN WILL NOT RETRACT

Replace defective parts (WP 0068 00).

MALFUNCTION

Incorrect, obstructed, worn, or broken extractors; broken or weak springs. CORRECTIVE ACTION

1. Check the tips (1) of the right-hand (RH) and left-hand (LH) cartridge extractors for obvious wear or breakage. Ensure the wider tip is on top.

2. Attempt to force RH and LH cartridge extractors apart to test for weak or unequal spring tension or obstruction between the RH and LH cartridge extractor and bolt. Remove RH and LH cartridge extractors and springs (WP 0068 00). Measure spring length (WP 0057 00). Replace springs, in pairs, if critical lengths are not in accordance with requirements.

Extractor Maxim Machine Gun

MALFUNCTION

Loose or cracked right-hand (RH) and left-hand (LH) cam followers.

CORRECTIVE ACTION

Manually test the RH and LH cam followers (1) for looseness and check for cracks on the top. Tighten nylon point set screws (2) as required.

LOOSE RH OR LH CAM FOLLOWERS OR NYLON POINT SET SCREWS

Tighten RH and LH cam followers (1). Tighten nylon point set screws (2). CRACKS

If cracked, replace RH and or LH cam follower. Install new nylon point set screw (WP 0068 00).

MALFUNCTION

Obstructed pawl; weak helical spring.

CORRECTIVE ACTION

Press the pawl (1) to test for weak spring action or an obstruction under the pawl. Replace helical spring if action is weak; clear obstruction.

Mark Bolt Face

SYMPTOM - Continued

Rounds will not extract/eject. MALFUNCTION

Obstructed bolt fingers; broken or weak finger springs. CORRECTIVE ACTION

Ensure welded pins (1) are present in the bolt finger area, and on the bolt face. Force the RH and LH bolt fingers (2) apart to test for weakness or unequal finger spring tension. If weak or unequal finger spring tension, evacuate to Depot Maintenance. (Marine Corps: repair at Unit Maintenance.)

Mk19 Machine Gun Bolt

BOLT FINGERS WEAK

Remove the covers. Remove the shoulder bolts and lift out the bolt fingers and finger springs. Check for the presence of welded keeper pins (1) on the bolt fingers and bolt.

MISSING KEEPER PIN (BOLT)

Install new bolt (WP 0068 00).

MISSING KEEPER PIN (BOLT FINGER)

Install new bolt finger (WP 0068 00).

WEAK OR BROKEN FINGER SPRINGS

Install new finger spring on both sides. Reassemble (WP 0057 00).

MALFUNCTION

Broken ogive plunger slotted washer.

CORRECTIVE ACTION

1. Remove the ogive plunger assembly (WP 0059 00) and inspect for broken slotted washer (1).

2. Disassemble ogive plunger (WP 0070 00). Inspect interior of the ogive spring housing and helical compression spring for proper lubrication. If lubrication is required, ensure parts are washed in solvent or RBC, dried, generously lubricated, and reassemble.

Ogive Plunger

BROKEN SLOTTED WASHER

Disassemble the ogive plunger assembly and replace broken slotted washer and assemble ogive plunger assembly (WP 0070 00).

END OF WORK PACKAGE

DIRECT SUPPORT

MK 19 MOD 3 40 MM MACHINE GUN, (NSN 1010-01-126-9063) UPGUNNED WEAPONS STATION MK 19 40 MM (NSN 1010-01-362-6513)

DIRECT SUPPORT TROUBLESHOOTING - ROUNDS WILL NOT FIRE

INITIAL SETUP:

Tools and Special Tools

Tool kit, small arms repairman,

SC 4933-95-CL-A07 with addition of SL-3-00607A (Marine Corps only) Tool kit, small arms repairman,

SC-5180-95-CL-A07 Tool set, intermediate maintenance, SL-3-08669A (Marine Corps only) Tool set, organizational maintenance, SL-3-08668A (Marine Corps only)

Materials/Parts

Dry cleaning solvent (item 11, WP 0124 00)

References

WP 0057 00 WP 0068 00 WP 0069 00 WP 0072 00 WP 0082 00

SYMPTOM

Rounds will not fire.

MALFUNCTION

Bent, broken, or missing helical compression spring.

CORRECTIVE ACTION

With feed slide assembly assembled, check presence and condition of helical compression spring (1).

With feed slide assembly assembled, check presence and condition of helical compression spring (1).

Mk19 Grenade Schmematic

DAMAGED HELICAL COMPRESSION SPRING.

Remove the damaged helical compression spring and install a new one (WP 0072 00).

MALFUNCTION

Defective firing pin, firing pin sear, or springs.

CORRECTIVE ACTION

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