Patent ID: 8201489

Claim:
A gas operating system for a firearm, said firearm comprising a barrel cantileverally attached to a receiver at a barrel trunnion and defining an axis and a bolt actuated operating system, said bolt actuated operating system further comprising a bolt carrier group slidable between first position proximate the trunnion and a second position along the axis, and a firing mechanism located distally on the firearm, behind a magazine well which is, in turn, behind the barrel and barrel trunnion, the gas system comprising: a. a gas manifold with fluid communication into a fore portion of the barrel through a tap; b. a hollow gas tube extending rearward from and having fluid communication with the gas manifold; c. a piston housing situated on the barrel trunnion and encompassing an end of the hollow gas tube thereby being in fluid communication with the same; d. a piston residing within said piston housing, capable of lateral motion along an axis of the barrel and having a portion of the piston which extends outside the piston housing when in a rearward orientation; and e. a spring contained within the piston housing positioned to bias the piston in a forward orientation; wherein the piston and piston housing present a relatively gas tight chamber and, upon firing of the firearm, released gasses are diverted through the tap, into the gas manifold, through the hollow gas tube and into the piston housing, where said gasses build pressure to actuate the piston in a rearward direction such that the piston extends outside of the piston housing, impinges upon and forces the bolt actuated operating system likewise rearward from the first position to the second position, releasing pressure therein and allowing the piston to be returned to a forward position when the bolt actuated operating system returns to its first position.