Because your question indicated deer and pronghorn with the "possibility" for elk, I'd still go with the 270. Go with a high b.c. bullet for the deer sized game and step up to a premium 150gr for the elk.
However I believe the 300WM would be "better" but NOT if you can't shoot it as well as the 270. Clearly the 300WM is not needed for the deer sized game.
Let us know what you decided.


My home is the "sanctuary residence" for my firearms.