THe 54cal would be just fine! It is easier to find 54cal stuff. If roundballs did not cleanly kill deer we would not use them. I know the roundball can be complicated with patch thickness, lubes, material, ect. The 1-48" twist works good for roundballs, conicals, and some sabots. My 54cal with a 1-48" twist loves the 425gr Hornady Great Plains with 100gr powder. You will not go wrong with the 54cal Lyman Deerstalker. Remember flinters like Real Black Powder and only that!