Walter Grass insisted the correct way is to replace the hinge pin, but I did watch him tighten a couple the "quick and dirty"( read cheap) way. He didn't peen the hook, rather, he expanded the hinge pin. He did this with the help of an employee by taking the covers off the pin and using a punch set in a vise as an anvil and another punch on the other end to transfer the impact of a shop hammer to the end of the pin. He also stretched the forearm iron by peening the backside with a punch that looked similar to a cold chisel that was rounded and polished on the end. By then bearing on the latch hook on the barrel, it pushed back against the receiver. He did peen the locking lug recess, but polished the punch marks out. when he finished, there were no visible peen marks.
Mike
