A firearm includes a barrel having a breech end. A receiver is engaged with the breach end of the barrel and defines a chamber. A vent path is through the barrel downstream from the breech end. A latch is downstream from the vent path. A bolt is at least partially inside the chamber. The bolt has a locked position to prevent the bolt from moving away from the breech end of the barrel and a released position that allows the bolt to move away from said breech end of the barrel.

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 firearms gas operating system. The firing pin retaining pin is oriented so as to expose its widest profile to the firing pins annular flange, increasing its service life. The bolt has a plurality of lugs extending from its forward end and an extractor recess. The extractor recess is constructed to accommodate an enlarged extractor claw while not undercutting the bolt lugs adjacent thereto. The extractor engages approximately 57% more of a seated ammunition cartridges rim as compared to some prior art AR15/M16 type extractors used with automatic firearms chambered in 6.8SPC. The result is an improved bolt and bolt carrier which provides for increased operational reliability.

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 firearms gas operating system. The firing pin retaining pin is oriented so as to expose its widest profile to the firing pins annular flange, increasing its service life. The bolt has a plurality of lugs extending from its forward end and an extractor recess. The extractor recess is constructed to accommodate an enlarged extractor claw while not undercutting the bolt lugs adjacent thereto. The extractor engages approximately 57% more of a seated ammunition cartridges rim as compared to some prior art AR15/M16 type extractors used with automatic firearms chambered in 6.8SPC. The result is an improved bolt and bolt carrier which provides for increased operational reliability.

A bolt action AR rifle can be prepared using a standard AR lower assembly and coupling it to a bolt action upper assembly. The bolt action upper assembly has a bolt action receiver containing a bolt. The method of forming a bolt action AR rifle can include: providing the bolt action upper receiver assembly; providing the standard AR lower AR receiver assembly having a pivot pin and takedown pin; inserting the pivot pin into the pivot pin receiver hole; pivoting the bolt action upper receiver assembly at the pivot pin until the takedown pin is aligned with the takedown pin receiver hole; and inserting the takedown pin into the takedown pin receiver hole.

A bolt action AR rifle can be prepared using a standard AR lower assembly and coupling it to a bolt action upper assembly. The bolt action upper assembly has a bolt action receiver containing a bolt. The method of forming a bolt action AR rifle can include: providing the bolt action upper receiver assembly; providing the standard AR lower AR receiver assembly having a pivot pin and takedown pin; inserting the pivot pin into the pivot pin receiver hole; pivoting the bolt action upper receiver assembly at the pivot pin until the takedown pin is aligned with the takedown pin receiver hole; and inserting the takedown pin into the takedown pin receiver hole.

A bolt carrier group for a firearm includes a bolt carrier, a bolt, and a cam pin. The bolt carrier includes a medial portion and a first and second outer portion. The bolt carrier slidably couples with a first elongated member at the first outer portion and a second elongated member at the second outer portion. The bolt is received within an inner volume of the bolt carrier. The cam pin is coupled with the bolt. The cam pin is positioned at least partially within the inner volume of the bolt carrier and extends through a top surface of the bolt carrier. The cam pin and the bolt are translatable and pivotable relative to the bolt carrier between a first position and a second position. The cam pin is configured to engage a recess of the second outer portion of the bolt carrier when in the first position.

A bolt carrier group for a firearm includes a bolt carrier, a bolt, and a cam pin. The bolt carrier includes a medial portion and a first and second outer portion. The bolt carrier slidably couples with a first elongated member at the first outer portion and a second elongated member at the second outer portion. The bolt is received within an inner volume of the bolt carrier. The cam pin is coupled with the bolt. The cam pin is positioned at least partially within the inner volume of the bolt carrier and extends through a top surface of the bolt carrier. The cam pin and the bolt are translatable and pivotable relative to the bolt carrier between a first position and a second position. The cam pin is configured to engage a recess of the second outer portion of the bolt carrier when in the first position.

A rifle includes a magazine well, a barrel detachably coupled to the magazine well, and a suppressor detachably coupled to the barrel. The barrel includes a forward barrel portion on an end of the barrel opposite the magazine well. The forward barrel portion includes a muzzle locking mechanism. The suppressor is configured to be retractable.

A recoil assembly for a rifle includes a barrel assembly, a bolt, bolt actuator, and a buffer assembly. The barrel assembly includes a barrel secured to a barrel extension. The barrel assembly is slidably received in the receiver and the barrel extension is coupled to a hydraulic buffer assembly located below the barrel extension. The hydraulic buffer assembly is configured and arranged to arrest rearward movement of the barrel assembly when the rifle is fired. An op-rod spring is coupled to an op rod extending that can be actuated by a gas piston assembly on the barrel. The op-rod spring is configured and arranged to arrest rearward movement of the bolt assembly.

Breechblocks for firearms, the breechblocks including a barrel axis and a barrel extension, including a bolt with cam pin and cam pin axis, and a bolt carrier which has at least one end face and an assembly groove and a substantially S-shaped cam slot with a locked position and an unlocked position, wherein the assembly groove at the locked position of the cam slot is subsequently formed substantially from behind in the forward barrel direction and is essentially U-shaped.