i have a 50 cal TC hawkin and shoot 90 grains blackpowder and 370 grain maxi ball bullet. TC also make the maxi hunter bullet. i'm not sure but i believe power belts are considered sabots because of the plastic attached to the bottom of the bullet. to shoot round balls most accurate you need a muzzleloader with a 1 in 66 twist. a 1 in 48 twist does fine for maxi balls and the like. thats the twist i have in my hawkin and it shoots real good out to about 100 yards or so.
KEEP THE WIND IN YOUR FACE
AIM SMALL, MISS SMALL.