US12529533 - System for delayed blow-back action firearm
Provided is a blow-back bolt and recoil spring/buffer system for an autoloading firearm action. The blow-back bolt includes a bolt body and an actuator that is longitudinally movable relative to the bolt body to a limited extent by manual cycling. The recoil spring/buffer system has a longitudinal guide rod with at least one recess, a release component and a forward abutment slidably arranged together on the guide rod, a recoil spring is configured to bias the release component forwardly, and at least one roller body is arranged between the release component and the forward abutment. When the roller body is engaged in the recess, the release component and forward abutment are longitudinally slidably detained relative to the guide rod. Rearward movement of the actuator by manual cycling engages and displaces the release component such that the roller disengages from the guide rod recess to allow undetained rearward sliding movement against the recoil spring.