Abstract: A receiver assembly for a firearm slidably and rotatably carries a bolt having a non-rotating cartridge extractor-guide at the forward end which allows the bolt to rotate relative thereto and the bolt head has locking lugs which engage a locking surface in the forward or barrel end of the receiver when the bolt is in the firing position. A flexible feeding ramp in the firing chamber surrounds the extractor and serves as a cartridge guide and pre-loads the bolt axially in the firing position. A firing pin carrier assembly provides axial center line absorption of the firing mechanism forces while providing an off center firing pin tip required for rimfire ammunition. During the initial firing sequence the feeding ramp absorbs vibrations caused by the moving components of the firing mechanisms and the impact of the firing pin and the subsequent shock of ignition, and bullet movement.

Abstract: This invention relates to a firearm and more particularly to a firearm having a bolt action in which a bolt is arranged for axial and rotational movement in a receiver and an extractor system operable in combination with the movement of the bolt relative to the bolt receiver. The bolt includes lugs having a locking surface which engages a locking wall formed on a cooperating lug on the receiver when the bolt is in the firing position. Both the locking surface and locking wall are arranged at cooperating angles and are conically shaped so as to insure that the axis of the bolt and receiver will be concentric when the bolt is locked in the firing position. In the event of a cartridge rupture the angle of the locking wall causes some of the forces generated by the rupture to be diverted at an angle from the axis, thereby minimizing the shearing stresses on the receiver lugs.