Two years ago, my friend brought his CVA inline .54 caliber with the same problem. He mounted a scope, and could not find where it was hitting. So we took out the bolt, and put it in a vice. Then we took a large piece of cardboard and painted a 5" red circle on it. We moved the target at 20 yards to where it looked lined up looking through the barrel. Then we moved the scope to the center of the red circle. When we finally got it all put back together, we began shooting. We knew the gun liked 100 grains of loose Pyrodex Select, and 300 grain LEE conical ballets. The scope was about 5 inches off. It was then a matter of tuning the scope to the rifle. After it was set, we cleaned the rifle, and I was impressed at the groups he was shooting at 50 yards after that. It seemed to be a nice shooting rifle, although it did like to push a little if you put more then 100 grains of Pyrodex in it. Good Shooting