My .45 caplock has a 40" Ed Rayl barrel with a 1:66 twist. With a 128 grain patched round ball it kills Tennessee whitetails DRT out to at least 75 yards. I've taken a pickup truck load from my farm, and haven't had to track one over 25 yards yet. I built the rifle as a chunk gun for the annual Alvin York shoot, but I've moved up to a .50 caliber flintlock with a 48" barrel for that event. The .45 is useful for stand hunting- - - -I wouldn't want to carry it far, though!
