Patent ID: 8479635

Claim:
A bolt catch assembly configured for operating with rimfire ammunition and incorporated into a firearm exhibiting a reciprocating bolt assembly within a receiver exhibiting an exposed chamber, an ammunition containing magazine engaging within the receiver at a communicating underside of the chamber, the receiver further including an internally supported and upwardly biased follower, a user engageable portion mounted to the receiver and vertically displacing an integrally formed catch, said assembly further comprising: an actuator housing exhibiting a perimeter and within which is defined an open interior, said actuator housing being configured to be seated upon an upper surface of the receiver such that said open interior communicates with the exposed chamber; a catch actuator supported in elevatable fashion upon an end of said actuator housing in engagement with the integrally formed catch, a tab portion of said catch actuator extending over the open interior established between said actuator housing and the exposed chamber; and upon discharging a remaining cartridge from within the magazine, the upwardly biased follower contacting and elevating said catch actuator and catch to an upper position for abutting and restraining forward travel of the reciprocating bolt assembly in order to establish a last shot bolt hold open condition, subsequent downward actuation of the user engageable portion releasing the bolt assembly.