Patent ID: 9658008
Date: 2017-05-23
CPC Classifications: F41A

Claim:
1. A firearm comprising: a frame with an upper receiver defining an elongated central bore bolt passage and formed of a first material; a bolt including a bolt carrier with a bolt head operable to reciprocate in the bolt passage between a forward battery position and a rearward retracted position; the bolt being biased in a forward direction; a bolt stop attached to the frame and having a protruding forward portion extending into the bolt passage; the bolt stop formed of a second material having a greater density than the first material; the bolt having an elongated contact feature adapted to contact the bolt stop during reciprocation of the bolt, and to prevent damaging contact between the bolt and the frame; wherein the elongated contact feature is a slot closely receiving a portion of the bolt stop; wherein the slot has an open forward end such that rotation of the bolt is permitted when the bolt is retracted rearward of a selected position; and wherein the bolt has a forward facing surface adapted to contact the bolt stop when the bolt is retracted rearward of the selected position and rotated, such that the bolt is maintained in the retracted position by the bolt stop contacting the forward facing surface.