I have a U.S. Common Rifle model 1817 - H. Deringer contract 1825, so she's 199 years old now... Still shoots pretty durn good. Several deer and last November a big buffalo cow. 75 grains of 2 f Olde Eynesford, and a linen patched .524 ball. .530s will work but you need a really thin patch. The bore aint perfect and thinner patches tear up .
On the buffalo, shot her at a little over 65 yards; the ball broke a rib on the way in, punched a thumb sized hole through the heart and was flattened against the hide on the far side . My son was carrying a U.S. Model 1819 Hall rifle. Same balls and load in the Hall. The Hall has a near perfect bore and is very accurate. I make paper cartridges for the Hall out of regular wax paper. Tear open the cartridge, charge the chamber, pop in the waxed paper wrapped ball; really shoots well.