I hunt with a .54 caliber Knight MK-85, and these are the only bullets I have used for years. I use the same loads for both Mule Deer and Elk, although the bullets I use, I believe, are 485 grains. I fire 105 grains of FFg black powder with them, and they hit hard and do what they are supposed to do. When a bullet is recovered (usually only from elk on the far end of hide side), the bullets are flattened out and almost the same weight. I do use an additional lube with them, though - makes loading easier. Can't go wrong with them!
Frank from NM