I have two classes of muzzle loaders, target guns and a single long rifle. Paper punching is obviously a different endeavor from shooting game, but the long rifle will shoot as well as I can with most any gun in offhand application and that w/o serious load development. 5 in 2" +\- at 50. Best I've ever done is 10 in a sub 3" group @ 100 yards, that with a Ruger#1 in .257 Roberts. Within reason I fail to see a significant difference in that level of dispersion.
I only shot that kind of group one time with the patch round ball, must have wobbled just right with the open sights