Well the Lyman Great Plains Hunter(GPH) is the same rifle as the Lyman Great Plains Rifle(GPR), except it has a fast twist barrel. You can buy either a GPR or GPH and the extra barrel in fast twist, or slow, depending on which model you originally purchased and accomplish what you want. My personal opinion, based on my personal preferances, would be to just buy a GPR in .54cal for shhooting round balls and forget a fast twist barrel. With a bit of tweaking on the sights, the GPR, shooting a .54cal roundball, will handle any game you are going after, within reasonable limits. By reasonable limits, I mean the rifle is easily capable of putting a ball into the kill zone, with the open sights, out to 100 yds. If your shooting skills will allow you to make that shot with confidence, the roundball will do the job on most big game you are likely to be hunting.