i'm not a G2 internal specialist :lol: ......but i know if a case is not sized down far enough, it will not lock up correctly, and the hammer will not cock on the G2 or encore. same effect with old model contenders, except they will cock, but just misfire.
if it's doing that with a empty chamber, then it's possibly not locking up completely. may have something to do with the locking lugs :? .......like 22hornet.......maybe a better explanation somewhere?