Abstract: A gun having a trigger mechanism comprising a pivotally mounted trigger (73) which is connected to rotate a pivotal sear and a reciprocal bolt carrier assembly having lugs (325) which are arranged to engage with the rear of the sear and a notch (717) in the top of the sear. Mounted on the pivotal axis of the trigger is a prop member (745) which is arranged to cooperate with an L-shaped nose (720) of the sear so that when the trigger is pulled to rotate the sear in a first direction out of engagement with the lugs (325) the prop member (745) is initially prevented from moving with the trigger by the nose (720) and when the lugs are released by the sear the sear is further rotated in the first direction by the lugs contacting the upper sear surface to free the member to move toward the trigger and under the nose (720). The prop member is then positioned under the nose (720) and thereby prevents the sear from rotating in a direction counter to said first direction until the trigger is released.

Abstract: A bolt carrier assembly has a housing (300) for supporting a bolt (317) and a P cross-sectionally shaped member (301) having the longer side of the P-shape secured to the housing, the P-shaped member being forwardly extended with respect to the bolt. The main drive spring (307) is located alongside the wrapped-over portion of the P-shaped member which main drive spring is arranged to provide motion to the housing and P-shaped member. An anti-bounce weight (354) is mounted inside the wrapped-over part of the P-shaped member and has a spring at one end which is compresed by the anti-bounce weight when the P-shaped member is suddenly retarded by the housing to which it is attached striking the barrel assembly. A latch (326-329) is spring biassed and shaped and dimensioned to interleave locking lugs (322) on the bolt (317), the latch being longitudinally retractable with respect to the housing.

Abstract: A gas operated gun having a receiver (1) including a rear wall (100) at one end and a barrel (10) at the other end and a bolt carrier assembly (3) reciprocal within the receiver is arranged to co-operate with a main drive spring (307) that urges the bolt carrier assembly toward the barrel. The gun is designed so that in one aspect of the invention on an automatic cocking cycle the bolt overtravels the cartridge feed station by an amount equal to or greater than the overall length of a live cartridge.In a further aspect, the gun is additionally designed using parameters calculated such that a substantially constant reaction is felt by a user. The parameters involved are essentially the product of sprung weight (the total weight in kg. of all components driven by the main spring).times.springing force (an average value of spring force that accelerates and retards the sprung weight).times.cycling distance (the length of allowable travel of the bolt carrier assembly in meters) is equal to (0.51).sup.2 .times.0.

Abstract: A drum magazine for a gun has a housing with a feed throat extending from the housing and within the housing are mounted concentric sprockets. The sprockets have serrations for nesting cartridges and each sprocket is independently rotatable with stops for limiting the rotation of the outer sprocket and stops limiting rotation of the intermediate sprocket. A latch is arranged to prevent rotation of the outer sprocket in a counter direction to the direction of feeding cartridges out of the magazine until the intermediate sprocket is rotated in the counter direction a predetermined amount. A connector is connected to the outer sprocket and passes through the outer sprocket to engage with the cartridges nested in the intermediate sprocket so that by virtue of the connector, the sprockets rotate together. A similar connector is provided between the intermediate sprocket and the inner sprocket. A U-shaped pusher is provided to push the last few remaining cartridges in the magazine out of the feed throat.