An improved bolt and bolt carrier with integral gas key having an extension nozzle threadedly secured and pinned to the gas key for use with a direct gas operated firearm is provided. The extension nozzle is designed to receive a portion of the host firearm's gas operating system. The firing pin retaining pin is oriented so as to expose its widest profile to the firing pin's annular flange, increasing its service life. The bolt has a plurality of lugs extending from its forward end. The extractor recess is constructed so that the face of the bolt is round and the adjacent lugs fully supported. The extractor engages approximately 17% more of a seated ammunition cartridge's rim as compared to the prior art AR15/M16 extractor. The result is an improved bolt and bolt carrier which provides for increased operational reliability.

A gas-operated firearm has a frame, a barrel defining a bore having a forward muzzle end and an opposed rear end defining a chamber, a bolt assembly received in the frame and operable to reciprocate between a battery position and a recoil position, the barrel defining a gas aperture communicating with the bore, a gas operating system connected to the frame, having a gas inlet, and operably connected to the bolt assembly to move the bolt assembly from the battery position toward the recoil position, and the gas inlet being forward of the gas aperture. There may be a gas conduit extending forward from the gas aperture to the gas inlet. The gas aperture may be proximate the rear end of the barrel. Unlike conventional gas-operated firearms, the barrel is free of contact with any other elements except proximate the rear end of the barrel.

A gas-operated firearm has a frame, a barrel defining a bore having a forward muzzle end and an opposed rear end defining a chamber, a bolt assembly received in the frame and operable to reciprocate between a battery position and a recoil position, the barrel defining a gas aperture communicating with the bore, a gas operating system connected to the frame, having a gas inlet, and operably connected to the bolt assembly to move the bolt assembly from the battery position toward the recoil position, and the gas inlet being forward of the gas aperture. There may be a gas conduit extending forward from the gas aperture to the gas inlet. The gas aperture may be proximate the rear end of the barrel. Unlike conventional gas-operated firearms, the barrel is free of contact with any other elements except proximate the rear end of the barrel.

A semiautomatic shotgun successfully uses the AR-10 receiver and the superior direct impingement gas system. A combination of locking lugs to maintain proper sequencing, a spring disposed inside of a gas impingement chamber, and a spring to cycle the action. Fouling is avoided using nickel-boron coated parts, permanent infusion of a dry film lubricant, and an angled gas port. A unique magazine feed lip and barrel extension feed ramp and the magazine maintaining the shells at a slight angle upward, and a bolt face having a rear facing partial bevel avoid jamming and snagging. The present invention also teaches raised gas tube and gas key to accommodate the larger bore of the shotgun. The combination achieves an AR-10 based shotgun which has the advantages of direct impingement cycling (less recoil, greater accuracy, etc) without fouling and/or jamming.

A semiautomatic shotgun successfully uses the AR-10 receiver and the superior direct impingement gas system. A combination of locking lugs to maintain proper sequencing, a spring disposed inside of a gas impingement chamber, and a spring to cycle the action. Fouling is avoided using nickel-boron coated parts, permanent infusion of a dry film lubricant, and an angled gas port. A unique magazine feed lip and barrel extension feed ramp and the magazine maintaining the shells at a slight angle upward, and a bolt face having a rear facing partial bevel avoid jamming and snagging. The present invention also teaches raised gas tube and gas key to accommodate the larger bore of the shotgun. The combination achieves an AR-10 based shotgun which has the advantages of direct impingement cycling (less recoil, greater accuracy, etc) without fouling and/or jamming.

Bolt carrier groups (BCGs) for weapon systems are provided herein. The BCG includes a carrier assembly, a bolt assembly, and a gas chamber disposed therebetween. The carrier assembly contains a carrier body that includes a shoulder, a piston surface, and an inlet port. The shoulder is disposed within the carrier body and contains a channel and the piston surface is located on the shoulder at least partially encompassing the channel. The inlet port extends through the carrier body and is configured for receiving propellant gas into the carrier body. The bolt assembly is at least partially contained within the carrier assembly and includes a bolt head opposite of a bolt tail where the bolt tail is at least partially protruding into the channel in the shoulder. The gas chamber is disposed between the carrier body, the piston surface, the bolt tail, and two gas seals disposed on the bolt assembly.

Bolt carrier groups (BCGs) for weapon systems are provided herein. The BCG includes a carrier assembly, a bolt assembly, and a gas chamber disposed therebetween. The carrier assembly contains a carrier body that includes a shoulder, a piston surface, and an inlet port. The shoulder is disposed within the carrier body and contains a channel and the piston surface is located on the shoulder at least partially encompassing the channel. The inlet port extends through the carrier body and is configured for receiving propellant gas into the carrier body. The bolt assembly is at least partially contained within the carrier assembly and includes a bolt head opposite of a bolt tail where the bolt tail is at least partially protruding into the channel in the shoulder. The gas chamber is disposed between the carrier body, the piston surface, the bolt tail, and two gas seals disposed on the bolt assembly.

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 production direct gas impingement semi-automatic AR-style rifle is converted to a single shot, straight pull bolt action rifle that includes: a) conventional rifle components, including an upper receiver and lower, trigger, trigger guard, barrel; b) a direct gas impingement semi-automatic firing mechanism including automatic gas actuated casing ejection, automatic gas actuated bolt and hammer reset, and automatic gas actuated cartridge reload functionality, including a bolt carrier with two production carrier gas key screw threaded receiving orifices and having no production carrier gas key, and a having a metal gas blocking and diverting mechanism attached to the bolt carrier in the place of a production carrier gas key. This inhibits semi-automatic operation of the rifle by disabling the automatic gas actuated casing ejection, bolt and hammer reset, and cartridge reload functionality. In some embodiments the bolt carrier assembly and aforementioned gas diverting block mechanism components are unistructurally formed.