I ran into a mounting problem with my T/C Thunderhawk. This is not my first scope mount but the first time I've run into this problem. When I went to sight in the gun, I ran out of windage adjustment. I ran the scope windage all the way to the left, but the gun was still shooting to the right. How do I correct this? I'm thinking some kind of shim between the mount and the scope. Any help would be greatly appreciated.