Round ball size for .72-caliber?

[Naphtali]

I want to try shooting round balls in my .72-caliber rifle. Joe Williams made the barrel (30-inch barrel, 1:72). I believe cut rifling is .006-inch. This will be the first time I have loaded round balls in any rifle. I intend to acquire linen for patching material, between .010 and .015 inch - that is, what I can find in sufficient quantity. I use short starter for conicals in the rifle and prefer to use RBs with sufficient diameter to warrant continuing to use it.

Having a choke or taper bore .725 inch at muzzle, .731-inch remainder, what are acceptable round ball [dropped] diameters? In terms of accuracy, if it matters significantly what might be lead:tin or lead:tin:antimony mix I cast, please identify what would be preferred.

[D. Taylor Sapergia]

Have Jeff Tanner make you a mold that drops a PURE lead ball of .710".  Use cotton denim, drill or twill of .018" which when loaded will crush to .015".  This will seal your bore, be easy loading with your starter and wooden rod, and give nice accuracy with ~ 120 gr. 2 Fg black powder.

[Daryl]

If using a ball that is of any hardness, for a .72- (not a 12 bore which is .729" to .730") - I would have Jeff cut me a 13 bore ball which is .705".
With that diameter, you will be able to load a 12 ounce denim patch with either pure or WW-type alloys.

I do this in my .69 as I had Jeff cut me a 15 bore mould, ie: .677". It casts .675" in pure lead and .677" in WW alloy. I load both with the 12 ounce denim and accuracy is wonderful- same as the larger .684" ball and 10 ounce (.0225")denim.

The WW ball is slightly more difficult loading, but hardly noticeable as I still have meat hooks for hands and decent arms to compliment them.