A bolt assembly has a rear block configured for connection at the rear end of the bolt passage, a bolt carrier configured to reciprocate in the bolt passage, a support element between the rear block and the bolt carrier, a first spring between the support element and the rear block, the bolt carrier defining a bore, the support element including a guide rod slidably received in the bore, and a second spring encompassing the guide rod, having a rear end abutting the support element, and a forward portion received in the bore. The bolt carrier may include a bolt carrier body, and the bolt carrier may include a weight portion movably connected to the bolt carrier body. The weight portion may define a through hole receiving an intermediate portion of the guide rod and an intermediate portion of the second spring.

A bolt assembly has a rear block configured for connection at the rear end of the bolt passage, a bolt carrier configured to reciprocate in the bolt passage, a support element between the rear block and the bolt carrier, a first spring between the support element and the rear block, the bolt carrier defining a bore, the support element including a guide rod slidably received in the bore, and a second spring encompassing the guide rod, having a rear end abutting the support element, and a forward portion received in the bore. The bolt carrier may include a bolt carrier body, and the bolt carrier may include a weight portion movably connected to the bolt carrier body. The weight portion may define a through hole receiving an intermediate portion of the guide rod and an intermediate portion of the second spring.

A firearm reliability system may include a charging handle insert and a variable bolt weight assembly. Other components of a firearm reliability system may include, but are not limited to, a buffer pressure plug, extractor springs, firing pin springs, one or more firing pins, and bolt buffers. The firearm reliability system may address weaknesses in the common rimfire AR bolt system. Using the firearm reliability system, malfunctions may be essentially eliminated. Each component of the firearm reliability system plays a part and interfaces with the others (i.e., the bolt weight spreads the impact on the buffer into a larger area, while reducing the speed at which the bolt impacts the backplate, which then reduces the energy transferred to the buffer pressure plug and thus the impact with the lower receiver).

A firearm reliability system may include a charging handle insert and a variable bolt weight assembly. Other components of a firearm reliability system may include, but are not limited to, a buffer pressure plug, extractor springs, firing pin springs, one or more firing pins, and bolt buffers. The firearm reliability system may address weaknesses in the common rimfire AR bolt system. Using the firearm reliability system, malfunctions may be essentially eliminated. Each component of the firearm reliability system plays a part and interfaces with the others (i.e., the bolt weight spreads the impact on the buffer into a larger area, while reducing the speed at which the bolt impacts the backplate, which then reduces the energy transferred to the buffer pressure plug and thus the impact with the lower receiver).

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.

Provided is a last round bolt hold-open mechanism for a firearm with a removable ammunition magazine and a longitudinally reciprocating bolt that automatically releases the bolt when a loaded ammunition magazine is inserted. The mechanism includes a frame mountable to a firearm receiver and having a pair of mounting flanges. A catch member is pivotally mounted on a pivot axle oriented transverse to the longitudinal reciprocation of the bolt and carried by the mounting flanges. The catch member has a rearward portion that moves between bolt blocking and bolt release positions and is spring biased toward the bolt blocking position. A forwardly extending finger is configured to be lifted by the presence of at least one ammunition cartridge in the magazine and, when lifted, causes the catch member to pivot to the bolt release position.

A device is movably attachable to an upper receiver of a firearm adjacent to a rear end of an ejection port on the upper receiver. The device is configured to move linearly in directions parallel to a longitudinal axis of the upper receiver to function as a forward assist to cause a bolt carrier of the firearm to move forward with respect to the upper receiver. The device comprises a shell deflector having a deflection surface configured to deflect spent casings ejected out of the ejection port when the firearm is in operation.

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 bolt catch device is disclosed. The bolt catch includes a movable surface configured to be positioned within a weapon so as to conditionally engage a bolt so as to prevent the bolt from rechambering a next round from a magazine, a tip configured to, in response to a received force, cause the movable surface to move so as to release the bolt, and a spring engagement feature configured to be positioned within the weapon so as to receive a spring within the weapon, wherein the spring within the weapon is configured to bias the movable surface toward a position which prevents the bolt from rechambering a next round.