US Patent 9377257 Systems for firearms

Provided in one aspect is an annular gas ring within or adjacent a barrel to increase the efficient transfer of pressurized gas to one or more gas ports, which may communicate the high-pressure gas from near the chamber distally to a piston to cycle the action of the firearm. Provided in another aspect is a modular quick-disconnect barrel assembly for long-stroke gas-operated firearms such as the AK-47, which allows barrel and gas systems to be replaced together simply by pulling a single pin, thereby allowing the caliber of the firearm to be instantly changed to 12-gauge shotgun or any dimensionally smaller rifle or handgun round. A novel forward-charging handle system is also provided that works with the modular quick-disconnect barrel assembly.