I think some of you guys missed the Elk part. If you are hunting Elk, the 308 or 30-06 is the only choice. Forget about the 7mm-08 or the 270 Win in a pistol for Elk. I use an 7mm-08, perfect for deer, not Elk. The 270 in a 15 barrel is also minimal, and really loses velocity in a short barrel.
Of course with well placed head and neck shots anything would work. I assume you want a good hunting round though.