Have not yet jumped into Muzzle loaders but have been doing some reading. Most of the scopes that come as a package on MLs are fixed 6 or 7 power scopes. Kinda of makes sense seeing that you probably would not take any shots over 150yards, ok 200 with some of the hotest loads. With that said a 6X will work well out to those ranges. Just something to think about.

I have a 6X on a .270 and it works fine out past 200yards.