If I get what Jon and possibly what Sharpshooter is saying take it all apart and try to slide the firing pin in to the stop. Push the cross pin in and make sure it goes in all the way to the stop. Somewhere in this time frame set your protrusion. If at anytime it does not fit together correctly stop and find out why. I will defer to Jon or Fred to advise on drilling anything out. I know what I would do but I am not conventional very often.