I have a 36 cal with a 42 inch "Montana" barrel, 1 turn in 48. It's a real tack driver with 20 gr of 3f under a patched RB. On a whim I tried loading a greased .357 148gr HBWC as a Minie ball. While my close up accuracy does no equal that of the RB, at 100 yrds it will hold 3 to 4 inches. I could never get the RB to stay tight out to 100 yards, 60 or 70 seems about max for minute of rodent head accuracy.