Mule Deer? I think wide open country, I'd take a .270 over a .30-06 but both would work fine, 150gr in the '06, and 130gr in the .270

anything from .243 to .338 win mag would be a good choice pretty much.

not sure a magnum is really required for a mule deer, in fact its probably what a .270 was made for. Alot of guys love the 7mm rem mag for muleys, but again why need a magnum?