cluttonfred
Member
As an offshoot of my earlier Modern carbine in... .30 carbine? and Dream carbine...part 2 threads, I wonder if anyone knows of a gun using a simple, delayed-blowback action which uses a gas piston to unlock the breech?
Presumably, if gas tapped near the muzzle is used to unlock the breech, then the bullet has almost or maybe already left the barrel by the time the breech opens and pressures would be substantially reduced, allowing more powerful cartridges or a lighter bolt compared to straight blowback actions.
To put it another way, say a rotating bolt is spring-loaded to rotate and lock on closing, the gun fires, the bolt remains locked in the breech, the bullet nears the muzzle, the gas piston kicks the bolt against the spring pressure to unlock it, and the bolt is then free to recoil as a normal blowback action now that pressures have dropped to safe levels.
Historical examples? Pros and cons? Thanks!
Presumably, if gas tapped near the muzzle is used to unlock the breech, then the bullet has almost or maybe already left the barrel by the time the breech opens and pressures would be substantially reduced, allowing more powerful cartridges or a lighter bolt compared to straight blowback actions.
To put it another way, say a rotating bolt is spring-loaded to rotate and lock on closing, the gun fires, the bolt remains locked in the breech, the bullet nears the muzzle, the gas piston kicks the bolt against the spring pressure to unlock it, and the bolt is then free to recoil as a normal blowback action now that pressures have dropped to safe levels.
Historical examples? Pros and cons? Thanks!