An assembly for holding a bolt of a firearm in an open position is disclosed. The assembly comprises a bolt catch pivotable about a first axis toward and away from a catching position. In the catching position, a portion of the bolt catch is within a path of travel of the bolt. A follower transfer adapter is pivotable about a second axis. The follower transfer adapter includes an engagement portion that is configured to engage a follower of a magazine. Optionally, the follower transfer adapter includes an overhang lip that extends transversely to the longitudinal axis of the firearm and into a path of travel of the follower to define the engagement portion. The engagement portion is positioned between the second axis and the bolt catch along the longitudinal axis of the firearm. A linkage transfers rotational movement of the follower transfer adapter to rotation of the bolt catch.

An assembly for holding a bolt of a firearm in an open position is disclosed. The assembly comprises a bolt catch pivotable about a first axis toward and away from a catching position. In the catching position, a portion of the bolt catch is within a path of travel of the bolt. A follower transfer adapter is pivotable about a second axis. The follower transfer adapter includes an engagement portion that is configured to engage a follower of a magazine. Optionally, the follower transfer adapter includes an overhang lip that extends transversely to the longitudinal axis of the firearm and into a path of travel of the follower to define the engagement portion. The engagement portion is positioned between the second axis and the bolt catch along the longitudinal axis of the firearm. A linkage transfers rotational movement of the follower transfer adapter to rotation of the bolt catch.

A semiautomatic firearm with redundant systems for reducing misfirings. A safety trigger is provided that is passively actuated in advance of a firing trigger. The safety trigger maintains redundant safety mechanisms that prevent inadvertent or accidental actuation of the firing trigger. The firing trigger can be configured for actuation with a very low magnitude or soft pull without compromising safety. For the disclosed embodiments, the safety trigger assures that the firearm is discharged only upon deliberate actuation of the firing trigger. In one embodiment, a trigger pull adjustment mechanism provides adjustment of the pull of the firing trigger to a desired force required by the operator. The disclosed trigger pull adjustment mechanism reduces the number of components and complexity of the machined parts over conventional trigger pull adjustment mechanisms.

A firearm bolt assembly for a self-loading firearm has an elongated frame defining a frame axis, a bolt connected to a forward end of the frame, a plurality of separate weights connected to the frame, and the weights being movable at least slightly with respect to the frame and to each other for movement along the axis. There may be a resilient spacer element between adjacent weights. There may be a resilient spacer element between one of the weights and a portion of the frame. The spacer element may be an O-ring. The weights may be connected to a rear portion of the frame. The weights may be tubular bodies each defining a bore. A portion of the frame may be received within the bore. The frame may define a rear portion having a first diameter, and a flange forward of the rear portion having a larger second diameter.

A firearm bolt assembly for a self-loading firearm has an elongated frame defining a frame axis, a bolt connected to a forward end of the frame, a plurality of separate weights connected to the frame, and the weights being movable at least slightly with respect to the frame and to each other for movement along the axis. There may be a resilient spacer element between adjacent weights. There may be a resilient spacer element between one of the weights and a portion of the frame. The spacer element may be an O-ring. The weights may be connected to a rear portion of the frame. The weights may be tubular bodies each defining a bore. A portion of the frame may be received within the bore. The frame may define a rear portion having a first diameter, and a flange forward of the rear portion having a larger second diameter.

A reciprocating bolt assembly has delayed blowback and a firing pin block. Features prevent out-of-battery firing, when the bolt assembly is not fully engaged to the firing chamber or barrel face, a movable member within a bolt body functions as a blocking member that blocks the firing pin and prevents the firing pin from striking a cartridge. In embodiments, the firing pin has two stop portions that the movable member can engage depending on the cycle status of the firearm. A reverse cam mechanism associated with the firing pin blocking provides a resistance to and delays blowback.

An ejector mechanism for a firearm. The ejector mechanism includes a claw-type extractor disposed opposite a ledge portion that includes an inclined face, the inclined facing being oriented to face toward a bolt face to help secure a shell casing to the bolt face during the extraction process. The claw-type extractor and inclined face, while providing positive retention of the shell casing during ejection, also cooperate to enable the shell casing to be dislodged by an ejector.

A firearm can have a bolt having a plurality of locking lugs that are configured to have a shear area that is larger than that of a standard M16/M4. A bolt carrier can have a bolt that has a double cut cam having an unlocking cam surface that has sufficient dwell increase to delay a start of unlocking when the bolt carrier is used in an M4 carbine. A stepped extractor pin may be provided that prevents disengagement of the extractor pin. A tube can be configured to provide gas from a barrel of the firearm to the piston via the carrier key. The tube can have a heat radiator formed from triangular shaped threads on at least a portion of the tube. A piston on the bolt and can have a plurality of rings including pairs of mating rings that are formed and maintained as a matched pair.

A firearm can have a bolt having a plurality of locking lugs that are configured to have a shear area that is larger than that of a standard M16/M4. A bolt carrier can have a bolt that has a double cut cam having an unlocking cam surface that has sufficient dwell increase to delay a start of unlocking when the bolt carrier is used in an M4 carbine. A stepped extractor pin may be provided that prevents disengagement of the extractor pin. A tube can be configured to provide gas from a barrel of the firearm to the piston via the carrier key. The tube can have a heat radiator formed from triangular shaped threads on at least a portion of the tube. A piston on the bolt and can have a plurality of rings including pairs of mating rings that are formed and maintained as a matched pair.

A reciprocating bolt assembly has delayed blowback and a firing pin block. Features prevent out-of-battery firing, when the bolt assembly is not fully engaged to the firing chamber or barrel face, a movable member within a bolt body functions as a blocking member that blocks the firing pin and prevents the firing pin from striking a cartridge. In embodiments, the firing pin has two stop portions that the movable member can engage depending on the cycle status of the firearm. A reverse cam mechanism associated with the firing pin blocking provides a resistance to and delays blowback.