Abstract: A buffer assembly for a firearm includes an internal assembly comprising a plurality of weights within a buffer body of a buffer and at least one magnet. The magnet at least partially offsets an inertial event that occurs during a firing action of the firearm.

Abstract: A handguard assembly for a firearm includes a handguard with an internal clamping area. A single-piece index block includes a securing portion for connecting to the handguard and an indexing extension for engaging an indexing feature on the upper receiver of the firearm. The handguard includes internal ribs that provide discrete clamping surfaces for engaging a barrel nut of the firearm. Connecting the index block to the handguard generates a continuous clamping action in the handguard which acts through the ribs to apply a radially-directed circumferentially-applied clamping force on a barrel nut through the discrete clamping surfaces. The indexing feature of the index block engages an indexing feature of the upper receiver to ensure proper alignment of the handguard and the upper receiver.

Abstract: A double-walled handguard for a firearm includes an inner tube and an outer tube connected by longitudinally-extending struts. A circumferential gap is formed between the inner and outer tubes. The handguard can be extruded as a blank and feature such as accessory rails and accessory mounting apertures can be machined into the blank to arrive at the desired configuration. Vent holes may be machined into the outer tube to provide a venting path for hot air in the circumferential gap. The double-walled handguard is expected to have increased strength compared to a single-walled handguard and better shield the user's hands from heat generated by the barrel of the firearm.

Abstract: An assembly for mounting a handguard on a barrel nut of a firearm. The firearm has a gas piston action that includes an operating rod. The assembly includes a tie rod having a reduced thickness middle portion that extends between the barrel nut and the operating rod. The tie rod has connectors at each end. Fasteners are inserted from opposite sides of the handguard and connect to the tie rod connectors. The fasteners are threaded into clamp blocks such that rotation of the fasteners applies compression on the handguard against the barrel nut and a generates a reactive tensile load in the tie bar.

Abstract: A method for securing an accessory to a firearm includes inserting a lug and a nut into an entry opening positioned between first and second opposite ends of a slot formed in a wall of the firearm. The lug restricts the nut from rotating about an axis of a threaded member with which the nut is in threaded engagement. The slot has a first width, the entry opening has a second width that is greater than the first width, and the nut has a major dimension that is larger than the first width and smaller than the second width. The method also includes sliding the lug and nut in the slot in a sliding direction toward the first end or the second end, and rotating the threaded member with respect to the nut to clamp the wall between a surface of the nut and a surface of the accessory.

Abstract: A firearm comprising an upper receiver and a charging handle is disclosed. A charging handle is coupled to the upper receiver and comprises a handle assembly rotationally coupled to a main body about a first and a second pivot point. The handle assembly includes a first handle having an edge nearest the main body and a latch extending from the first handle parallel to the main body for interfacing with the upper receiver in a first position, a second handle having an edge nearest the main body, and a push rod positioned between the edge of the first handle and the edge of the second handle, such that when force is applied to the second handle, energy is transferred through the second handle to the push rod and to the first handle, moving the latch into a second position.

Abstract: An upper receiver for a firearm. The firearm includes a barrel extending forward of the upper receiver and a buttstock extending rearward of the upper receiver. The upper receiver includes an arcuate surface formed in a wall of the chamber. The arcuate surface changes direction of gases that are directed rearward in the chamber such that the gases are vented from the upper receiver in a non-rearward direction.

Abstract: An upper receiver for a firearm. The firearm includes a barrel extending forward of the upper receiver and a buttstock extending rearward of the upper receiver. The upper receiver includes forward gas escape ports through a frame of an ejection port through which spent casings are ejected. The upper receiver further includes a trough formed on an inside surface of the frame. The trough collects gases in the chamber and distributes the gases to the gas escape ports. The gas escape ports are covered by an ejection port door when a shell is not being ejected.

Abstract: An accessory mounting system for use on a firearm includes an elongated opening having first and second ends and an entry aperture between the first and second ends. A fastener with a major dimension larger than the minor dimension of the elongated opening, but small than the width of the entry aperture can be inserted into the entry aperture and slid toward either of the first and second ends of the elongated opening. The fastener may be, for example, a T-nut or a screw-like fastener with a circular head. If a T-nut is used, it can be inserted into the elongated opening transverse to the elongated opening and slide to either end in the transverse orientation so it spans across the elongated opening without having to turn it.

Abstract: A firearm comprising an upper receiver and a charging handle is disclosed. A charging handle is coupled to the upper receiver and comprises a handle assembly rotationally coupled to a main body about a first and a second pivot point. The handle assembly includes a first handle having an edge nearest the main body and a latch extending from the first handle parallel to the main body for interfacing with the upper receiver in a first position, a second handle having an edge nearest the main body, and a push rod positioned between the edge of the first handle and the edge of the second handle, such that when force is applied to the second handle, energy is transferred through the second handle to the push rod and to the first handle, moving the latch into a second position.

Abstract: An upper receiver for a firearm. The firearm includes a barrel extending forward of the upper receiver and a buttstock extending rearward of the upper receiver. The upper receiver includes forward gas escape ports through a frame of an ejection port through which spent casings are ejected. The upper receiver further includes a trough formed on an inside surface of the frame. The trough collects gases in the chamber and distributes the gases to the gas escape ports. The gas escape ports are covered by an ejection port door when a shell is not being ejected.

Abstract: An upper receiver for a firearm. The firearm includes a barrel extending forward of the upper receiver and a buttstock extending rearward of the upper receiver. The upper receiver includes an arcuate surface formed in a wall of the chamber. The arcuate surface changes direction of gases that are directed rearward in the chamber such that the gases are vented from the upper receiver in a non-rearward direction.

Abstract: A buffer assembly for a firearm includes an internal assembly comprising a plurality of weights and a dead-blow biasing member in the form of a coil compression spring, stack of wave washers, a compression washers, or a compliant portion integrally formed in a rear end cap of the buffer assembly. The dead-blow biasing member is positioned between a flat end of one of the weights and a rear end cap of a buffer body or between flat ends of adjacent weights.

Abstract: A handguard assembly for a firearm includes a handguard with an internal clamping area. A single-piece index block includes a securing portion for connecting to the handguard and an indexing extension for engaging an indexing feature on the upper receiver of the firearm. The handguard includes internal ribs that provide discrete clamping surfaces for engaging a barrel nut of the firearm. Connecting the index block to the handguard generates a continuous clamping action in the handguard which acts through the ribs to apply a radially-directed circumferentially-applied clamping force on a barrel nut through the discrete clamping surfaces. The indexing feature of the index block engages an indexing feature of the upper receiver to ensure proper alignment of the handguard and the upper receiver.

Abstract: A handguard assembly for a firearm includes a handguard with an internal clamping area. A single-piece index block includes a securing portion for connecting to the handguard and an indexing extension for engaging an indexing feature on the upper receiver of the firearm. The handguard includes internal ribs that provide discrete clamping surfaces for engaging a barrel nut of the firearm. Connecting the index block to the handguard generates a continuous clamping action in the handguard which acts through the ribs to apply a radially-directed circumferentially-applied clamping force on a barrel nut through the discrete clamping surfaces. The indexing feature of the index block engages an indexing feature of the upper receiver to ensure proper alignment of the handguard and the upper receiver.

Abstract: A handguard assembly for a firearm includes a handguard with an internal clamping area. A single-piece index block includes a securing portion for connecting to the handguard and an indexing extension for engaging an indexing feature on the upper receiver of the firearm. The handguard includes internal ribs that provide discrete clamping surfaces for engaging a barrel nut of the firearm. Connecting the index block to the handguard generates a continuous clamping action in the handguard which acts through the ribs to apply a radially-directed circumferentially-applied clamping force on a barrel nut through the discrete clamping surfaces. The indexing feature of the index block engages an indexing feature of the upper receiver to ensure proper alignment of the handguard and the upper receiver.