A firearm stock with barrel-centering feature has an elongated body defining an elongated receiver channel and an elongated barrel channel, the receiver channel defined in part by a flat floor surface facing in upward direction, the receiver channel defined in part by opposed sidewalls extending above the floor surface, a fastener facility at the rear of the receiver channel operable to connect to the tang of the receiver, and a lateral adjustment facility forward of the fastener facility and operable to secure the receiver in a selected lateral angle of pivot about the fastener facility, such that the barrel is centerable within the barrel channel to avoid the barrel touching the stock. The lateral adjustment facility may include a set screw having an axis parallel to the floor surface of the stock. A pair of set screws opposing each other may secure the action in a selected lateral position.

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 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.

There is a multi-caliber weapon system. The multi-caliber weapon system comprises: a frame body, with a front body portion, a middle body portion, and a rear body portion, and including: a plurality of frame flanges, each frame flange being coupled to an interior of the frame body and extending upwardly therefrom; a barrel, removably coupled to the front body portion of the frame body, including: a plurality of barrel rings, each barrel ring being disposed around a circumference of the barrel and spaced along a length of the barrel, wherein the barrel rings are disposed on the frame flanges; a chamber, removably coupled to the middle body portion of the frame body, and removably coupled to the barrel; and a bolt, removably coupled to rear body portion of the frame body, removably coupled to the chamber, and including: a bolt face, removably coupled to a front bolt portion.

The invention relates to small firearms and constitutes a device for attaching a barrel to the receiver. A clamping attachment of the barrel to the receiver allows for various sighting devices to be installed directly on the breech section of the barrel, thus allowing the barrel to be detached from the firearm without losing the alignment of the sight against the barrel.

A firearm includes a receiver body is provided herein having a plurality of barrel-tightening portions with at least one relief recess therebetween and relief recesses defined in the body on either proximal end. The relief recesses and barrel-tightening portions are sized to allow the barrel-tightening portions to be tightened and loosened independently of each other. A barrel assembly is removably coupled to the receiver body.

A handguard assembly and related method are provided. The handguard assembly can include a fastener assembly that installs in a handguard bore of a handguard. The fastener assembly can include a fastener head including first threads threaded in a first direction, a shaft extending from the fastener head, the shaft including second threads threaded in a second direction opposite the first direction, and a lock tab threadably engaging the second threads, the lock tab including a tab head. When the fastener assembly is converted from a retracted mode to an extended mode, the tab head can wedge into a barrel nut groove to secure the handguard to the barrel nut thereby impairing the handguard from rotating and/or sliding relative to the barrel nut. The shaft can thread into the lock tab when the fastener assembly is installed relative to the groove, with the overall length of the fastener assembly increasing as the tab head moves in the groove.

A receiver body is provided herein having a plurality of barrel-tightening portions with at least one relief recess therebetween and relief recesses defined in the body on either proximal end. The relief recesses and barrel-tightening portions are sized to allow the barrel-tightening portions to be tightened and loosened independently of each other.

A barrel nut assembly with an improved attachment paradigm may feature a collet body circumscribed by a tightening band and release lever such that actuation of the release lever will selectively loosen or tighten the band and collet such that the barrel nut assembly may be positioned over or off a joint between a barrel and receiver in a firearm.

A handguard for mounting on a firearm with a housing axis, including: a housing with a slit and with a clamping device including a lever with a center element which lies in a normal plane to the housing axis in a through-opening. It has a recess in its central region, a thread at one end, a lever arm at the other end, and a nut with an internal thread. According to the invention, the center element has a conical nut section. In the assembled state, a nut is screwed onto the thread and thus the center element is arranged in an annular groove of the travelling nut so as to make contact with the center element.