With a slower twist rate, you can load "hotter" and still maintain accuracy with a PRB. Every rifle I own with a 1 in 48" twist will not shoot a PRB at any velocity over 1550 fps. Other fellas report they get good accuracy with more energetic loads, but that is my experience in my rifles. With the slower twist rate, I can launch prb's at 2000+ fps and maintain accuracy. However, I don't use that heavy of a load for hunting, having just done it on occasion to see what is possible. I rarely use more than 60 grains, and 70 grains is really pushing it. In my long barreled .54's, I get 1750 fps with 70 grains (60 gr. 1600 fps) of Swiss 3f, which is more than plenty. I have killed a lot of deer with my 1 in 48" Investarms "Hawken" in .54, using only 60 grains of powder for about 1500 fps. In my 10.5 lb. Pedersoli RMH (1 in 65") I do shoot 90 grains of Swiss 3f to get 1900 fps, as the weight of the rifle makes recoil more tolerable. If I was to go after bigger game than deer, that would be my choice. The Hornady Great Plains Bullet in .54 shot well in most of my rifles using moderate powder charges. It is (or was, as it is no longer produced) a solid base bullet, unlike a hollow based Minie. I have never shot a Minie in .54, but have fired a bunch of .58 Minie's in my original Civil War era muskets with good results. As far as effect on game, I place myself in position to get very close shots, and in my experience the PRB's kill every bit as good, if not better than conicals. Perhaps at longer ranges, 100 yards or more, the conicals would be more effective, but that is not my way of hunting. Nowadays, I am a one buck a year deer hunter, my latest taken a few weeks ago at just over 20 yards. The .530 PRB smacked him right down propelled by the aforementioned 60 grain Swiss 3f charge.