Provided is a side charging handle system for an AR-pattern firearm with an upper receiver having an internal longitudinal bore for receiving a bolt carrier assembly for longitudinal reciprocation therein, a side longitudinal guide slot, and a side charging handle having an engagement pin extending through guide slot to engage the bolt carrier assembly.

System for a multi-caliber self-loading action. Specifically, the system is comprised of a multi-position locking assembly and a self-regulating gas assembly. The multiposition locking assembly is comprised of a bolt carrier, a spring, a bolt, a lock, and a cam assembly. The cam assembly will interface between the bolt carrier and the bolt to rotate the bolt through the bolt carrier. The lock will interface with the bolt, to lock the bolt in at least one locked position based on the caliber of the round inserted. The self-regulating gas assembly directs gas from the gas regulation to at least one piston cup, which will then cause the piston to act on the multi-position locking assembly.

System for a multi-caliber self-loading action. Specifically, the system is comprised of a multi-position locking assembly and a self-regulating gas assembly. The multiposition locking assembly is comprised of a bolt carrier, a spring, a bolt, a lock, and a cam assembly. The cam assembly will interface between the bolt carrier and the bolt to rotate the bolt through the bolt carrier. The lock will interface with the bolt, to lock the bolt in at least one locked position based on the caliber of the round inserted. The self-regulating gas assembly directs gas from the gas regulation to at least one piston cup, which will then cause the piston to act on the multi-position locking assembly.

The invention is a bolt carrier with a modified cam path that prevents undesired contact between a cam pin and the sidewall of an upper receiver.

The invention is a bolt carrier with a modified cam path that prevents undesired contact between a cam pin and the sidewall of an upper receiver.

Provided is a side charging handle system for an AR-pattern firearm with an upper receiver having an internal longitudinal bore for receiving a bolt carrier assembly for longitudinal reciprocation therein, a side longitudinal guide slot, and a side charging handle having an engagement pin extending through guide slot to engage the bolt carrier assembly.

Provided is a side charging handle system for an AR-pattern firearm with an upper receiver having an internal longitudinal bore for receiving a bolt carrier assembly for longitudinal reciprocation therein, a side longitudinal guide slot, and a side charging handle having an engagement pin extending through guide slot to engage the bolt carrier assembly. Also provided is a compact bolt carrier system including an upper receiver having an internal longitudinal bore for receiving a bolt carrier assembly for longitudinal reciprocation therein and a longitudinal recoil spring guide channel positioned above the internal longitudinal bore. The bolt carrier assembly has a bolt carrier body configured in length to reciprocate substantially entirely within the upper receiver and has a top lug extending into the recoil spring guide channel. A recoil spring is in the recoil spring guide channel.

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 magazine well for a firearm having an angled spine receiving portion. A charging handle for a firearm having latch that extends below a bottom surface of a crossbar. A bolt carrier for a firearm having a pair of vent holes disposed in the indented portion and at least one additional vent hole on indented portion adjacent to the pair of vent holes. A bolt catch for a firearm having a receiving portion curved to match the contours of a human thumb. A scope assembly for a firearm having markers on a scope and amount that correspond to the same radial positions. A bolt for a firearm having a plurality of ribs disposed on a main body and extending from a front end toward a tail portion of the bolt.