As others have already said first suspect is the dot sight. I have used them for 70 yards and under where they rise and shine. If I am shooting 100 yards or beyond a 2.5x8 variable is going on the gun. Second I also think that bullet may be heavy in that gun. In your average .454 that bullet would be fine but that gun is made for light bullets at warp speed. Even though the bullets aren't leaving a key hole doesn't mean they are correctly stabilized. I would try some of the bullets such as the Barnes intended for the .460 and stick a good scope on it and give it a whirl.