I looked it up, 1 inch at 25 and 2 inches at 50.

Take a look at this site, these are the bullets I use. I don't think they have problems shooting them at higher speeds. They are lead, but they are saboted. I just feel a lead bullet like this expands better at muzzle loader velocities vrs a jacketed bullet made for a pistol.

Precision Rifle Bullets

Paul