Tinker - sounds as if you have everything under control and know what to do with your loads and wad columns. GREAT!

The accuracy you've got so far is good enough to smack a moose or elk, but I'd like to see more 'power' myself. Your load is equivalent to about an 80gr. 2F load in a .60 muzzleloading flintlock rifle.

I found the OxYoke wads gave great accuracy in my .50 Rolling block rifle, much better than any of the card wad combinations I tried. I don't know what it was about them, but it is difficult to argue with success. The circle wad is a good idea for centering the ball - good stuff.