Abstract: A delayed blow back bolt action for a firearm includes a bolt and a slide which are movable together in the receiver frame and are disposed for limited movement with respect to one another. The bolt and slide have cooperating camming surfaces which cause a relatively large displacement of the slide in relation to the displacement of the bolt when the forces attendant to the discharge of a round in the firearm are initially applied to the bolt. The bolt is provided with a lug which engages a locking recess in the receiver frame of the firearm, and the lug and recess have cooperating camming surfaces, such that a surface of the recess provides an opposing force to the force generated by the discharge of a round from the firearm, which force is exerted against one end of the bolt. As such a force is supplied to the end of the bolt, the locking lug is forced out of the locking recess, thereby camming the slide in a direction which is along the longitudinal axis of the bolt.