I have killed 3 elk in my life. The first was with a 308 the last with with a 357 magnum carbine, the middle was with a 30-30
I think you will be fine. Just make sure you shoot it well and the gun will do its part.
The only one that gave me any trouble was the 357 carbine. The Elk was a young Cow elk I got to 50 yards and I aimed for the double lung shot, she took a step at the last second (forward and down hill in to a small wash)and the shot went back a little bit hitting the shoulder.The elk ran about 60 yards before it dropped.
While I love my 357 magnum marlin, it will not be going on any more elk hunts with me.