Abstract: Provided is a drop-in unit end of stoke firearm recoil damper for a firearm having a recoil buffer that linearly reciprocates in a recoil tube. The drop-in damper unit includes a housing cup and a resilient cushion. The cup is configured to fit within a recoil tube and has an internal flange. The resilient cushion is configured to fit within the housing against the flange. The cushion has a tubular shape with a longitudinal central opening and first and second frustoconical end surfaces. Both of the frustoconical end surfaces extend in a forward direction. The cushion is resiliently deformed toward reversing the direction of the frustoconical surfaces in a rearward direction when impacted by the buffer.

Abstract: Provided is a cartridge feed guide particularly useful for a pistol-caliber firearm with a blow-back bolt. It includes a barrel with a chamber with an open entrance to receive a cartridge. A guide member is situated rearward of the chamber entrance and has a pair of generally upwardly extending and laterally spaced apart pillars configured to guide a cartridge being pushed by the bolt from a magazine by limiting lateral angular of the cartridge. The guide member can also provide a fulcrum on which a vertical angle of the cartridge pivots as it is being chambered.

Abstract: Provided is a drop-in unit end of stoke firearm recoil damper for a firearm having a recoil buffer that linearly reciprocates in a recoil tube. The drop-in damper unit includes a housing cup and a resilient cushion. The cup is configured to fit within a recoil tube and has an internal flange. The resilient cushion is configured to fit within the housing against the flange. The cushion has a tubular shape with a longitudinal central opening and first and second frustoconical end surfaces. Both of the frustoconical end surfaces extend in a forward direction. The cushion is resiliently deformed toward reversing the direction of the frustoconical surfaces in a rearward direction when impacted by the buffer.

Abstract: Provided is a cartridge feed guide particularly useful for a pistol-caliber firearm with a blow-back bolt. It includes a barrel with a chamber with an open entrance to receive a cartridge. A guide member is situated rearward of the chamber entrance and has a pair of generally upwardly extending and laterally spaced apart pillars configured to guide a cartridge being pushed by the bolt from a magazine by limiting lateral angular of the cartridge. The guide member can also provide a fulcrum on which a vertical angle of the cartridge pivots as it is being chambered.

Abstract: For use on a firearm having a removable ammunition magazine, a longitudinally reciprocating bolt, and a pivoting bolt catch member, the present invention provides an empty ammunition magazine bolt hold open mechanism having a longitudinally extending axel pivotally mounted to the firearm for rotation about a longitudinal axis. The axel has a forward lever arm that extends transversely from the axis and is positioned to be engaged by a magazine follower when the magazine is empty of ammunition. Displacement of the forward lever arm causes rotation of the axel. The axel has a rear portion configured to engage the bolt catch and cause pivotal movement of the bolt catch member when the axel is rotated.

Abstract: For use on a firearm having a removable ammunition magazine, a longitudinally reciprocating bolt, and a pivoting bolt catch member, the present invention provides an empty ammunition magazine bolt hold open mechanism having a longitudinally extending axel pivotally mounted to the firearm for rotation about a longitudinal axis. The axel has a forward lever arm that extends transversely from the axis and is positioned to be engaged by a magazine follower when the magazine is empty of ammunition. Displacement of the forward lever arm causes rotation of the axel. The axel has a rear portion configured to engage the bolt catch and cause pivotal movement of the bolt catch member when the axel is rotated.