Patent GB-1268300-A (GB)
Title: Improvements in guns
IPC: F41A15/14
Filed: 1970-09-11
Abstract: 1,268,300. Guns. COLT'S Inc. 11 Sept., 1970 [12 Sept., 1969], No. 43642/70. Heading F3C. A gun comprises a receiver 12, a bolt and bolt carrier assembly 62 and a supporting mount, which includes guiding means 72 operatively connected to the assembly 62 and supporting the assembly in its operation. A releasable means, e.g. a latch 108, detachably connects the supporting mount to the receiver 12 so that on actuation of the releasable means the assembly 62 and supporting mount cap, as a unit, be removed from the receiver. In the construction shown the supporting mount comprises a recoil buffer 58 and the guiding means a pair of rods 72 releasably connected to the buffer 58 and projecting through lugs 84 in the assembly 62. Springs 90 surround the rods 72 and are interposed between the assembly 62 and the buffer 58 for driving the assembly in counter recoil. The recoil buffer includes a spring loaded plunger 64 which engages both the bolt 52 and the bolt carrier 82, the plunger having at its inner end an apertured piston to provide in cooperation with a fluid in the buffer a damping action (Fig. 1, not shown). In counter recoil the bolt 52 and bolt carrier 82 are locked together by a cam follower 226 in the form of a vertically movable pin which, when the bolt 52 approaches the battery position is withdrawn from an aperture 236 in the upper surface of the carrier 82 by cams 252 and thus on the bolt being held in its battery position is able to continue its movement with the carrier 82 and traverse a cam slot in the bolt to rotate and lock the bolt in its battery position (Fig. 3, not shown). The bolt and bolt carrier assembly is driven by a gas piston and cylinder arrangement which also provides a guide for the movement thereof. The cylinder is held in the receiver by a hand grip 20. The carrier 82 is provided with cam paths 216, 218 which co-operate with a roller 220 and a wiper pad (222, Fig. 9, not shown) respectively of a pivotable actuator 204 to operate belt feed pawls 196 of a feed assembly. The feed assembly also comprises a feed tray 170 having a stripping slot 182 for the passage of a stripping lug 156 of the bolt 52, a cover 174 and a spring urged cartridge guide 184 provided with a belt retaining pawl 190, the feed assembly being pivoted at one end to the receiver and being latched to the receiver at the other. The mounting for the latch 180 of the feed assembly also provides a pivoted mounting for an ejector assembly 270, 272, 274, 280, the ejector lever 270 and crank 272 having a lost motion connection therebetween so that actuation of the ejector is only effected during recoil (Fig. 11, not shown). An extractor and cartridge positioning and centring devices are provided on the forward end of the bolt 52 (Fig. 4, not shown). A trigger group 114 is slidably mounted on and latchable to the receiver 12 for movement between a forward and rearward position (Fig. 1, not shown). In its movement between these two positions the sear 124 of the trigger group 114 engages the bolt carrier 82 so that the assembly 62 is moved into its cocked position. In the cocked position the trigger mounting shaft 138 which is movable transversely of the trigger acts in one transverse position as a safety (Fig. 8, not shown). The barrel 10 of the gun is mounted in the receiver 12 by means of a spring loaded latch 38, the barrel 10 being held in the correct alignment with respect to the receiver by a web 42 of the latch co-operating with a slot 44 in a latching boss 34 of the barrel. A rear sight 284 is mounted on the receiver 12 a peep sight member 286 thereof being received in a sight bracket for transverse and vertical adjustment.