gas efficent semi bolt

[iknowmy3tables]

I thought of this bolt system, I don't know if I've seen something similar, but can't find now. but hear is a gas acuated auto loading mechanism, its to reduce the displaced gas that often in blow-forward bolt systems, their are other ways to mod the bolt but they often can restrict air flow, and are hard to make in small bolts


the air from the chammber goes into the piston pushed the bolt forward, then dumps when the gun is fired. also the reason I have a needle valve is for a very fast refil two stage chammber design, like my getto multi shot spud rifle