An upper receiver assembly for a firearm having an upper receiver with an integral barrel nut, a handguard assembly and a barrel nut assembly with a barrel and lock nut is provided. The barrel is received by the upper receiver and is secured directly to the upper receiver using the lock nut. The upper receiver also includes an integral handguard mounting member to which the handguard assembly may be directly attached. The upper receiver assembly allows the user to attach both the barrel and handguard assemblies directly to the upper receiver, independently of one another.

An upper receiver assembly for a firearm having an upper receiver with an integral barrel nut, a handguard assembly and a barrel nut assembly with a barrel and lock nut is provided. The barrel is received by the upper receiver and is secured directly to the upper receiver using the lock nut. The upper receiver also includes an integral handguard mounting member to which the handguard assembly may be directly attached. The upper receiver assembly allows the user to attach both the barrel and handguard assemblies directly to the upper receiver, independently of one another.

A handguard assembly for installation on a firearm includes a handguard, an index block, a first fastener, and a second fastener. The handguard includes first and second clearance apertures and the index block includes first and second threaded apertures. The first and second fasteners extend through the respective first and second clearance apertures and threaded into the respective first and second threaded apertures. The first and second fasteners define respective first and second longitudinal axes that are non-parallel and non-collinear with each other. Tightening the first and second fasteners with respect to the index block secures the handguard to the index block and prevents movement of the handguard relative firearm.

A handguard assembly for installation on a firearm includes a handguard, an index block, a first fastener, and a second fastener. The handguard includes first and second clearance apertures and the index block includes first and second threaded apertures. The first and second fasteners extend through the respective first and second clearance apertures and threaded into the respective first and second threaded apertures. The first and second fasteners define respective first and second longitudinal axes that are non-parallel and non-collinear with each other. Tightening the first and second fasteners with respect to the index block secures the handguard to the index block and prevents movement of the handguard relative firearm.

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.

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.

Quick take-down firearms and methods of using quick-take down firearms. The quick-take down includes an upper receiver coupling and a barrel coupling. The quick take-down can be unlocked by sliding a sliding lock collar in a translational motion to an unlocked position to release locking elements from a locked configuration. In the unlocked position, a barrel and handguard may be installed onto and removed from the upper receiver of the firearm. Releasing the sliding lock collar returns it to a locked position, securing the barrel and handguard to the upper receiver.

A firearm, top cover, and feed lever. The feed lever includes a feed lever body having a feed lever track, wherein the feed lever body is configured to be pivotally mounted within a topcover assembly, and wherein the feed lever body is configured to pivot in response to a force transmitted by a roller of an operating group to the feed lever track during cycling of the firearm. The feed lever further includes a feed lever track first end, wherein the feed lever track first end comprises a feed lever track exit portion configured to receive the roller of the operating group after the roller exits the feed lever track via the feed lever track exit portion as the firearm cycles.

A Universal Custom Recoil Solution will comprise of, a provided Firearm or barrel, prismatic shaped shell housing mounted or connected to the Gas Block Base, a Gas Block Base with pathways to direct firearms gas pressure from firing bullet into device interior pushing a Counter Weight, and Spring to counter act the firearms recoil when fired. This device is fitted to or around a provided barrel where the Counter Weight and spring are mounted on and reciprocate from front to back of the systems interior volume. The systems main function is to create a counter balance to the firearms kinetic energy by providing a moving mass, to counter the recoil from the firearms action movement when firing. The gas pressure is also expelled and redirected allowing the device to cycle synergistically with the firearm actions.

A firearm handguard assembly system is disclosed. The system comprises a handguard including at least four apertures, a barrel nut having a first threaded end and a second smooth end, the threaded end coupled to the handguard, and an index block including at least four apertures, the index block coupled to the handguard by at least four screws, each screw having a head and a tip, the tip threaded through: one of the at least four apertures on the index block, and one of the at least four apertures on the handguard.