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 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 firearm handguard is disclosed. The handguard comprises a first side section, a second side section coupled to the first side section by a plurality of interlocking fingers, and a bottom section coupled to the first side section and the second side section. The first side section and the second side section each contain at least one accessory mounting aperture. The first side section and the second side section are comprised of a polymer material having molded therein a reinforcement liner including at least one reinforcement aperture. The at least one accessory mounting aperture is aligned with the at least one reinforcement aperture.

Abstract: A firearm accessory mounting system includes a mounting assembly coupled to a firearm accessory, a mounting fastener, and a mounting bolt. The mounting fastener is rotatable between a locked positioned and an unlocked position. The mounting bolt is coupled to the mounting fastener for rotating the mounting fastener between the locked position and the unlocked position.

Abstract: A forward assist assembly movable between a standby position and an engaged position in a forward assist bore of a firearm. The assembly includes a button and an single-piece pawl. The single-piece pawl includes an integrally-formed pivot boss supporting the pawl in the button for pivotal movement with respect to the button. The pivot boss also transfers a linear actuation force from the button to the pawl to move the assembly into the engaged position. The single-piece pawl also includes an integrally-formed finger having an engagement surface for engaging a ratchet tooth on the bolt carrier in the engaged position. The single-piece pawl also includes an integrally-formed retaining surface to retain the forward assist assembly in the standby position in the forward assist bore. The single-piece pawl also includes an integrally-formed stop surface to abut a portion of the button in the standby position.

Abstract: 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.

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 plunger interfacing with the edge of the first handle and the edge of the second handle, and a spring, such that when force is applied to either handle, the plunger is pushed into the main body and energy is transferred to the handles, moving the latch into a second position.

Abstract: 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.

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: 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 plunger interfacing with the edge of the first handle and the edge of the second handle, and a spring, such that when force is applied to either handle, the plunger is pushed into the main body and energy is transferred to the handles, moving the latch into a second position.

Abstract: An accessory mounting mechanism with a top portion consisting of a ring and a bottom portion consisting of a clamp is disclosed. The ring accepts an accessory. The ring is coupled to a clamp, which is configured to engage a firearm. The clamp further includes at least two detachable wedges, a cross bar, and a tightening mechanism, which may be either a thumb nut or a throw lever. The cross bar is threaded through both detachable wedges. Tightening by way of the thumb nut or the throw lever applies force against the wedges and the firearm simultaneously, which pushes the accessory upward into the ring and secures the clamp to the firearm.

Abstract: A firearm handguard assembly system, the system comprising a handguard, wherein the handguard includes a first aperture and a second aperture on a first side, and a third aperture and a fourth aperture on a second side. A barrel nut which includes a groove around the outside diameter ahead of the threaded portion which is threaded onto the upper receiver to provide a mounting surface for the handguard. A locking mechanism is placed around the handguard containing the barrel nut, locked in place by at least a notched cross bolt and a locking cross bolt. The bolts are threaded through a first and second clamp block and the handguard. The bolts pass through the clearance afforded by the groove in the barrel nut without interfering with the various other components located above the barrel nut. An optional indexing plate may be placed between the barrel nut and the handguard to prevent rotation of the barrel nut.