Building a 7.62x39 Ar pistol upper and having some issues.
I built it using a Superlative arms piston kit.
I went with a 10.5in barrel with a carbine length gas system.
Superlative says the gas system should cycle perfectly fine with the 7.62x39 build.
With it wide open, it only extracts the shell casings about 3/4 of the way then stops(jams in place). I can grab the charging handle and easily finish the cycle to eject the spent round and chamber the next round.
Alignment of the gas block seems good, is it possible that the carbine length gas system, being so close to the end of the barrel is not creating enough back pressure before clearing the end of the barrel?
Anyone do a similar build? have similar issues?