A rotating bolt firearm may be configured to fire a .308 cartridge. However, the firearm may have a reduced weight in comparison to standard .308 rifles. The firearm may have many components typically used in a .223 rifle. The firearm may include a barrel extension with an extractor gap, which allows a .308 bolt to fit within a .223 sized barrel extension. The firearm may comprise an elongated magazine well in comparison to a .223 mil-spec rifle. The firearm may weigh less than 6.8 pounds with a 16 inch barrel, or less than 6.3 pounds with a 10.5 inch barrel.

A rotating bolt firearm may be configured to fire a .308 cartridge. However, the firearm may have a reduced weight in comparison to standard .308 rifles. The firearm may have many components typically used in a .223 rifle. The firearm may include a barrel extension with an extractor gap, which allows a .308 bolt to fit within a .223 sized barrel extension. The firearm may comprise an elongated magazine well in comparison to a .223 mil-spec rifle. The firearm may weigh less than 6.8 pounds with a 16 inch barrel, or less than 6.3 pounds with a 10.5 inch barrel.

A modular bolt assembly may include a bolt body, a striker assembly, and one or more removable bolt, head having a floating fixing pin, The removable bolt head may have a cartridge engagement surface, a back end that removably mates with a bolt body, and a floating firing pin with a front end that contacts a cartridge primer, and a rear end that receives force from the striker assembly. Bolt heads may be included for different caliber cartridges, allowing the modular bolt assembly to be used with different types of ammunition, the floating firing pin prevents the striker assembly from directly contacting a chambered round without the bolt head, thereby preventing catastrophic failure during use if a boll head is not present and properly positioned.

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 multi-position 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 multi-position 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.

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.

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.

The invention relates to a breech system for a firearm, having a bolt receiver and a bolt; the bolt receiver is embodied in the form of a hollow cylinder at least with engagement means protruding radially inward and there is also at least one bolt head, which has outward-protruding engagement means that correspond to the inward-protruding engagement means; the bolt head is supported in rotary fashion on a bolt carrier and there is also a bolt body, which is able to slide on a bolt head shaft of the bolt head, and between the bolt body and the bolt carrier, there is at least one compression spring, which tends to move the bolt body in the direction toward the bolt head; and on the bolt head shaft and on the bolt body, there are means that produce a rotation of the bolt head when the bolt body is slid on the bolt head shaft.

The invention relates to a breech system for a firearm, having a bolt receiver and a bolt; the bolt receiver is embodied in the form of a hollow cylinder at least with engagement means protruding radially inward and there is also at least one bolt head, which has outward-protruding engagement means that correspond to the inward-protruding engagement means; the bolt head is supported in rotary fashion on a bolt carrier and there is also a bolt body, which is able to slide on a bolt head shaft of the bolt head, and between the bolt body and the bolt carrier, there is at least one compression spring, which tends to move the bolt body in the direction toward the bolt head; and on the bolt head shaft and on the bolt body, there are means that produce a rotation of the bolt head when the bolt body is slid on the bolt head shaft.

A bolt carrier group assembly for a firearm includes at least one metallic bolt carrier group component with an outer metallic surface and at least one insert with an outer surface. The outer surface is at least flush with the outer metallic surface, and the at least one insert has a lower coefficient of friction compared to the at least one metallic bolt carrier group component.