IMO, Certainly would and would be preferable to the 425. But the truth is that a buffalo can fall to anything available to load in your .54 cal., including a roundball. TheSouix, Pawnee, Osage, Commanche, Cheyenne, etc. made a living killing them with arrows.Maybe the best would be one of those 500+Hydracons or a heavy Bullshop in the appropriate size for your rifle. Sure would be alot of fun to plug one from 220 yards out with one them heavy conicals. Were it not for Yellowstone, 70 grains powder and a 500 grain bullet would have made the poor critters extinct.

Happy Hunting, Phil