Given a bullet that doesn't blow up the 308 is all the elk gun you'd need. I and my wife have killed a number of elk with 308s and I know probably 30 other hunters in Idaho, Wyoming, Montana, Nevada and Utah that have done it many many times, going all the way back to the 1960s.
In my experience the very best 150 grains bullets will exit them only about 1 time in 2. The 165 grain bullets of the same types do a bit better and the 180s are about the best.

My friend Randy dropped one in the Jarbidge wilderness of Nevada at 415 yards with a factory loaded Remington Core-Lokt and it was the largest bull he ever got. Used a scout rifle I made him with a 2X scope on it too. The barrel is 18" long so an 18" 308 with a 2X scope was just fine. Not that there is anything wrong with larger calibers and longer barrels with huge scopes in them, but I stand on 50+ years of experience when I tell hunters that they don't actually NEED such long heavy rifles for elk. Carry and use them if you like them, But you NEED to know how to hunt.

But in my years of hunting elk, (going back to the 60s) I would say that the 308 Winchester, used with good bullets' (my overall favorites are the 165 and 180 grain Nosler Partitions) is all the elk gun you'd ever need for 99.5% of all the shots you'd ever need to take at elk.

Last edited by szihn; 10/18/21.