I have two of the Pedersoli Frontier .32's, a flint and a percussion. Both like the load of a Hornady .310" ball, .015" Ox-Yoke (or whatever their new name is) pre-lubed patch, and 30grs. Goex FFFg. From a rest at 50 yards, the rifles average a 1" to 2" group.
The biggest factor (at least in my case) is the shooter ability.
This is closely followed by: Amount of fouling, wind, rain, snow, taxes, death, taxes, license, dealer prep, taxes, delivery charges, assembly fees, taxes, gas mileage, time between oil changes, and......oh yeah, taxes.