I shoot my 12" PSA upper only with a can on it. I have the adjustable gas block turned all the way down and it functions as smooth as silk: light recoil and lock-back on last round.
This actually surprised me because I thought the gas block would shut off when turned all the way in, but it didn't.
This actually surprised me because I thought the gas block would shut off when turned all the way in, but it didn't.