Abstract: An attachment for a maching gun with automatic firing mechanism operated by barrel recoil has a tubular jacket positionable over the barrel. A rear end of the jacket is securable to the gun casing and its forward end surrounds the muzzle of the barrel. A restrictor screws into the forward end of the jacket and slides over the barrel muzzle to form a chamber between the muzzle and a transverse wall of the restrictor. Overpressure relief ports are formed in the transverse wall of the restrictor, and exhaust ports are located in the side wall. Gas pressure is built up in the chamber after a blank round has been fired to cause the barrel to recoil a sufficient amount to actuate the automatic firing mechanism. Once the barrel recoils past the exhaust ports, the gas pressure is released to stop the recoil motion. The recoil stroke and rate of fire are adjusted by adjusting the position of the restrictor in the jacket, to adjust the position of the exhaust ports.

Abstract: An improved receiver assembly adapted for use in a weapon that fires cartridges fed into the same from an ammunition belt having metal links. The assembly includes a trunnion block having a surface and two oppositely disposed sides. The surface is delimited on two opposed sides thereof by retaining means formed along said edges of the trunnion block. A wear plate is adapted to removably overlie the surface, and absorbs contact from the metal links. The wear plate is planar, being made of hardened spring metal, preferably steel, type AlSl C 1045, hardened to R.sub.c 48-52. Two opposed edges of the wear plate have fastening means, preferably in the form of C-shaped flanges. These resiliently grip the retaining means to coact therewith in securing the wear plate to the trunnion block. A manually manipulatable tongue is formed on one of the flanges of the wear plate to facilitate placement and removal of the same.

Abstract: The invention disclosed is a man-portable multi-shot weapon capable of firing relatively large caliber projectiles e.g. 38-40mm at a rapid rate and to the conversion of a similar existing single-shot weapon to multi-shot capability. The multi-shot weapon comprises a barrel, a breech frame on which the barrel is mounted, said breech frame defining a lateral opening through opposite sides of the frame for receiving a magazine having a plurality of chambers to accomodate relatively large caliber projectiles, said magazine being rotatably mounted in said opening in such a manner that the chambers may be successively brought into a firing position in alignment with the barrel, and firing means for firing a projectile when in the firing position.