Ruger Mark 1 I got an old Mark 1 from my Dad recently. It is unusual in that it has a factory muzzle brake on it. My Dad bought it back in 1958 from a fellow that had a trigger job done on it and was using it for competition. I shot it some back in the 80s and it worked flawlessly. When I got the pistol from my Dad last month (he has not been using it at all) I completely took the gun apart, cleaned it, then reassembled it. Reassembly can be tricky on these pistols. I then took it to the range and started shooting. Most of the time it shot without any problem, but about every fifth or sixth shot it would send a double down range. It wouldn't go full auto, it would just send two quick shots down range with one pull of the trigger. The next pull would send one or sometimes two again. For those of you much wiser than I, could it be something I caused by improper assembly? Could the sear be worn out and need replacing? Does the trigger need replacing? Do I need to replace the springs? First, I am going to disassemble, inspect all the trigger parts for wear, and then carefully reassemble the gun. I will see if that fixes the problem. If that doesn't work, I will slowly start replacing trigger assembly parts until it stops doing the double fire. Any advice or suggestions would be greatly appreciated. I would really like to continue to use this pistol.