Well, both calibers have more then enough energy to take a deer at twice that range, neither is dropping hardly at all, at 100-200 yards. Another thing for consideration, energy doesn't make up for a bad, or less perfect shot, whatever rifle you get, make sure you are good enough with it, to deliver a humane and lethal kill, to whatever you are hunting. A 30-06 in the butt, is as deadly as .270 in the leg. In all honesty, both cartridges will get the job done, for sure, it just depends on how much recoil you want to deal with, which, even then, is a tiny difference between these two cartridges. But, the choice is up to you, if you want to shoot heavier bullets, get the 30-06, if you want to hunt game with lighter bullets, get the .270