I have killed two elk. My spike bull died using a 150gr interlock from a 30-06, placed tight behind the shoulder. He only took a few steps before going down. My second elk was a cow, killed using a 140 accubond from a 270win, placed tight behind the shoulder. She went down instantly. Some folks really like the magnums, and for good reason, if the shooter can be accurate. Shoot what you like, as long as you shoot it well.