SecondChance, you're worry is I think what caused me problems. The different shells produced different results. When I sight in this year I'll keep it to the copper solids I hunt with. That and a properly used gun rest to sight in with and I should be set.
The Muzzle Loader that originally made me think of this question on my slug gun should be at the store ready to pick up, along with a scope... I should be plenty busy before hunting season. Now if I can just find some time to hunt...