A bolt assembly is provided for a firearm. The bolt assembly comprises a block adapted to connect to a firearm frame and a bolt carrier adapted to reciprocate within the frame. The bolt assembly comprises a support element between the block and the bolt carrier. The support element is adapted to reciprocate within the frame with respect to the cap and with respect to the bolt carrier. The first and second spaced apart parallel rods are connected to the cap and extending from the cap. The bolt carrier defines a pair of spaced apart bores receiving the rods. A first spring is interposed between the block and the support element, a second spring is received on the first rod, and a third spring is received on the second rod.

A bolt assembly is provided for a firearm. The bolt assembly comprises a block adapted to connect to a firearm frame and a bolt carrier adapted to reciprocate within the frame. The bolt assembly comprises a support element between the block and the bolt carrier. The support element is adapted to reciprocate within the frame with respect to the cap and with respect to the bolt carrier. The first and second spaced apart parallel rods are connected to the cap and extending from the cap. The bolt carrier defines a pair of spaced apart bores receiving the rods. A first spring is interposed between the block and the support element, a second spring is received on the first rod, and a third spring is received on the second rod.

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.

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.

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 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 firearm mount, components thereof, and associated methods. The firearm can be configured for use with an AR-15 style firearm or other type of firearm. The firearm mount is adapted to securely hold the firearm assembly in position for cleaning, maintenance, and/or gunsmithing tasks. The firearm mount can include a lock configured to selectively lock and unlock a firearm assembly thereon.

A firearm mount, components thereof, and associated methods. The firearm can be configured for use with an AR-15 style firearm or other type of firearm. The firearm mount is adapted to securely hold the firearm assembly in position for cleaning, maintenance, and/or gunsmithing tasks. The firearm mount can include a lock configured to selectively lock and unlock a firearm assembly thereon.