Jim, the box says .452, but i measured the bullets at .4515; Regardless, i have the pet load for the rifle, i know the trajectory to 150 yards, and i have bullets, powder, sabots, and primers for the next 15 or 20 years (about 300 shots).
T.R., i am very happy with the Wolf. I would not replace it with any other muzzleloader. It is short, handy, balances well, and it is very very accurate. Also, it has a crisp, "breaks like glass", 3 lb. trigger.