I have been asking for Remo O/U informatin but also would like to know if someone can tell me how to fix a problem I am having with it. The top firing pin hangs up when I go to open the gun. I have been told it is the timing and is due to wear on the levers that are compressed when the gun is opened that cock the gun. I tried putting a shim on top of the lever but this did not help. Any suggestions? Jim