Not much of a whitetail hunter, but I have killed many dozens of caribou, most of which tend to be similar in size. I've used many different rifles, from 223 up through 375 or 340. The bullet characteristics matter more than anything, but the cartridges in the middle 270/7mm-08 thru 30-06/300 Mag seem to be best suited. The 6mm has done a lot of killing for me, but the immediate "tip-over" factor seems to be better with similar bullet types with 0.020" more bullet diameter. The heavier rifles, contrary to what some people think, tend to be somewhat less disruptive due to their bullet construction with typical bullets. Obviously, using a deer weight (and construction) bullet in the 375 will change that tendency.
