Big River
there were a couple of studies floating around a while back done on thousands of moose in Europe (They call them elk over there, I think) shot with various cartridges from 6.5X55 up to the 375 H&H magnum. There was NO significant difference in how far the animals traveled in any of the cartridges when shot placement was the same. Bases on that, you might be going the wrong way in cartridge size if you want quicker kills. You might want to emulate some of the Alaska crowd that kills big black bears with 223s, and use a smaller round that you can use to surgically remove parts of the central nervous system.
In the back of my mind, I am wondering what a 257 Weatherby Magnum would do to those critters-
Royce
Based on your wording, your study presumes the animal is harvested.
In wild conditions, during rifle season, after the Elk have been bugled poked and smoked for 3 months you can expect your shot opportunities can be few and far between, and the few you do get may be less then idea.
Sure, if you are hunting elk on a gated preserve, a .223 with a 60gr NPT might be all you need. But if you are hunting in the real world, a .338 is a better option.
