Use an Ox-Yoke Originals Lubed Shooting Patch, center it over a hole, press a 50 cal round ball into the patch until the ball protrudes below the flat surface. The patched ball can then be easily centered over the muzzle and rammed home with a starter. The plastic design does not soak in the lube from the patch like a wooden loading block does resulting in a more consistent shot pattern. Designed for 50 cal round balls.