well, if I was hunting for elk, bear, or moose and happened to come across a nice deer, Id shoot it with anything I was packing. Did just that a few years ago when I took a small 4x4 mulie with a 350 grain Speer MagTip out of my 416 Rem Mag when he stepped out 75 yards away when I was hunting moose. Killed it, but no better than a 117 grain bullet out of a 257 Roberts would of
no need for anything larger than a 30-06 for most general deer hunting. Some special applications may require something larger, like : close range brush hunting - 444 marlin or 45/70, or long range field hunting - 300 Ultra Mag or similar