Originally Posted by
Ned Christiansen
The hammer spring is not in right and is not detenting the trigger pin, so the trigger pin has walked out a bit, allowing the trigger to go crooked, so it can't interact with the hammer like it's supposed to, but you didn't mention any pins sticking out. So I think more likely, the disconnector is holding the hammer just enough to let the thing work semi most of the time, but it's right on the edge, so sometimes the counter-recoil is enough to jar the hammer off the disconnector. With the strigger still pulled from the previous shot, it goes bang. My guesses...... either way it's something that needs to get fixed right away.