Lugerdoc may help us, he is a real expert on mechanics of Lugers. It may not be cocking! The firing pin may not be catching on the sear bar when the action is worked. The sear bar is the little flat bar that rocks back and for to work. To actuate by hand you push IN on the front end from the side. The sear bar will return to the cocking position by the sear spring after you release the thunb pressure. I am sure I could fix it if I had it in my hands. I had one in my shop the other day that had the sear bar plunger (disconnector) put in backwards. I fixed this one, and it had over rotation problems in addition to the backwards parts.
