I switch between a 7mm remington magnum and a 300 winchester for elk. I have seen elk shot from 150 yards heart/lung run for a 1/4 mile with a 7mm. These are very tough animals. Even with the 300 i am always making sure to get ready for a second shot. .308 is a great deer gun, but i don't think i would feel confident in its knockdown power for elk. On another note....my grandfather shot every elk he ever took with a 300 savage. I don't think he ever took a shot farther than 100 yards though. I would go with a 30-06 or 7mm as a deer/elk gun. They are not overkill, but have the knockdown power needed. I prefer the 7mm over every other. it shoots flat(2-3 inches of drop at 300 yards with reloads), and will knock anything you want down.