Patent ID: 8640598
Filing Date: 2014-02-04
Classification: F41A

Abstract:
1. A system for operating a firearm bolt carrier, wherein the firearm fires one of a centerfire rifle or centerfire pistol cartridge, the system comprising: a receiver that carries the bolt carrier, wherein the bolt carrier includes a first strike surface and a second strike surface for receiving operating forces; a barrel coupled to the receiver, wherein the barrel includes a gas port for tapping expansion gases from the barrel; a monolithic sleeve piston that extends around the rifled barrel, wherein the monolithic sleeve piston acts to operate the bolt carrier in response to the expansion gases and to draw heat away from the barrel; an expansion chamber that receives the expansion gases from the gas port and that moveably receives the monolithic sleeve piston, wherein the expansion gases in the expansion chamber act against the monolithic sleeve piston and thereby move it towards the bolt carrier; a first operating rod for transferring a first operating force from the monolithic sleeve piston to the first strike surface of the bolt carrier; and a second operating rod for transferring a second operating force from the monolithic sleeve piston to the second strike surface of the bolt carrier.