11. Install breech insert (1) in receiver assemblies with damaged threads as follows:
Dry cleaning solvent is FLAMMABLE and TOXIC and must be kept away from open flames and used in a well-ventilated area. Use of rubber gloves is necessary to protect the skin when washing grenade launcher parts.
Appropriate eye protection is recommended when cleaning your weapon and/or its parts.
b. Clean the stripped hole in receiver assembly using a bore brush (TM 9-1005-249-10, TM 9-1005-31910, or TM 05538C10/1A (Marine Corps only)) to remove or loosen debris. Clean with dry cleaning solvent (item 9, app D) to remove debris and oils.
c. Apply surface primer (item 16, app D) to the breech insert (1) threads and shoulder area as well as to the receiver assembly hole that has the stripped threads. The primer should be applied to the shoulder area of the hole as well. Allow the primer to dry completely.
d. Apply a coat of sealing compound, DEVCON F (item 18, app D), to the breech insert (1) and the hole area in the receiver assembly. Install the breech insert as if being threaded. When the breech insert is in the final assembled position, flush to 0.007 inch (0.018 cm) below the breech surface of the receiver assembly, remove all excess sealing compound from the breech insert face, including the notches in the breech insert for the torque wrench adapter. Be sure all excess sealing compound is removed from the firing pin hole in the breech insert, including the rear area where the firing pin makes contact with the breech insert. Insert a pipe cleaner (item 6, app D) from the rear of the grenade launcher and through the firing pin hole.
e. Reassemble the back plate to the receiver assembly and place a C-clamp against the breech insert (1) and the back plate. Tighten the C-clamp only enough to hold the breech insert in a tight position to the receiver assembly. Do not bend back plate inward. Let the sealing compound cure for 24 hours.
f. To be sure the repair is satisfactory, remove C-clamp. Use the torque wrench adapter and torque wrench and apply 55 in.-lb (6.22 N-m) reverse torque to the breech insert (1). The breech insert should not move or loosen. If the breech insert loosens, turn the grenade launcher in as unserviceable.
ARMY TM 9-1010-221-23&P AIR FORCE TO 11W3-9-4-2 MARINE CORPS TM 07700A-23&P/2 NAVY SW 370-AE-MMI-010
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