Well it sounds like an excellent load you were shooting. Were you swabbing the barrel between shots? If so, were you doing it the same way every time?

A lot of time, people start too far away when working up a load. I like 25 yards until it shoots a hole on the bull. Then I back up to the other distances. It always seems to work better for me that way then going out and starting at the extreme distance.

If you're using loose powder, start your loads at 80 grains and work up from there.. also you might have a powder junkie rifle and it likes strong loads. Perhaps try a 110 grains. Its hard to say what a rifle and load will do. Good luck.