A mounting rail can be added to an air rifle by clamping a clamp to the air cylinder of the air rifle. The clamp has a monolithic clamp body that includes the mounting rail, a base, a left jaw and a right jaw. The left and right jaws are attached to the base. A clamp actuator can draw the jaws together to clamp onto the air cylinder. The base can include a mounting rail such as a Picatinny rail. As such, clamping the monolithic clamp body onto the air cylinder adds a mounting rail to the air rifle.

A barrel mounting system for a firearm includes a longitudinal axis, a receiver, and a barrel detachably coupled to the receiver by upper and lower barrel mounting features above and below the barrel bore centerline. The lower mounting feature may comprise a clamping block compressing a lower breech end portion of the barrel against the receiver. In one embodiment, a pair of lower securement fasteners extend through the clamping block and threadably engage the receiver to draw the block into engagement with the receiver. The upper mounting feature may comprise a securement fastener compressing an upper breech end portion of the barrel against the receiver. The upper and lower mounting features form a triangular bolting pattern and balance moment forces created by the compressive forces of coupling the barrel to receiver with the fasteners.

A firearm having a threaded barrel-receiver connection, with a threaded receiver opening for cooperative engagement with a threaded barrel. The receiver is also compatible with a clamping system for engagement of an unthreaded barrel, so that threaded and unthreaded barrels may be used interchangeably. The threads of the receiver may have a flat crested thread profile for sliding engagement upon installation of an unthreaded barrel.

A barrel unit for a firearm, including a barrel with a barrel axis, muzzle and a barrel end opposite the muzzle, on which at least two barrel lugs are formed, and a barrel extension with a barrel receptacle and a first end and a second end, wherein inwardly extending locking lugs are formed on the first end, to work together with a bolt, and inwardly extending barrel locking lugs are formed closer to the second end than the locking lugs. A barrel cam on the outer surface cooperates with a cam lug arranged on the barrel extension to fix the barrel in a predefined end position.

A free-floating rifle rail and barrel locking system that provides a barrel assembly and rail assembly, which is detachable from the main body of a rifle without tools. This is advantageous for quick field breakdown and/or rifle modification. The user has the option to disassemble the rifle for easy transport, to change barrel length, to change barrel caliber or change rail configurations. The rails are free-floating, meaning the rails do not come in contact with the barrel and thus do not impact the precision of the rifle.

Firearms, particularly rifles, including an upper housing having a barrel, where the barrel and the upper housing are interconnected by means of a guide. In order to improve the connection, the guide includes corresponding prismatic guide surfaces that extend in parallel with the barrel shaft when the firearm is mounted and ready to fire, and the barrel is secured to the upper housing by a tensioning element that can rotate in the upper housing about an axis of rotation that extends normally with respect to the firearm center plane, and the tensioning element includes a tensioning portion and an actuating portion.

The present disclosed subject matter relates to a housing for a firearm with an exchangeable barrel, comprising a bushing into which the barrel root of the exchangeable barrel may be inserted in the axial direction. The bushing has a slot in the axial direction and a clamping device for bringing the slot from a starting position into a narrowed position. The bushing is configured to receive the barrel root in a press-fitting manner when the slot is in the starting position and has a spreading device for bringing the slot from the starting position into an expanded position.

A mounting mechanism has a base upon which a rotating cam is mounted. The cam has a lobe which extends beyond the perimeter of the base when the cam is in a first position and remains within the perimeter of the base when the cam is in a second position. A detent is used to lock the cam in the first position. The detent includes a leaf spring positioned on the cam which defines a kink. The kink is engageable within a niche in the base when the cam is in the first position. An accessory attached to the mounting mechanism may be attached to a structure using the mounting mechanism. The base fits within a slot in the structure and the lobe of the cam engages the structure when the cam is in the first position to lock the mounting mechanism and the accessory to the structure.

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 bedding block for mounting a barreled action for a rifle to a stock can include an elongated body configured to receive the barreled action for the rifle in a semicircular channel defined in top surface of the elongated body. The semicircular channel can have a first radius, the barreled action can have a second radius, and the first radius can be less than the second radius.