My experience mirrors others. Except I have never killed a BIG bull. We hunt for meat and many years the only elk I saw was the one I killed, whether it was a raghorn, spike, cow, and even a couple of calves in the mix.

Besides not killing a big mature bull, all the elk I have killed died easier than a mature whitetail buck.
Killed one with a bow, it ran about 40 yds.
Shot one running once, it made it about 30 yds or less.
Made a bad hit on a little bull right before dark, hit him to far back. Found him about 100-150 yds dead within an hour of daylight.
One cow when shot through the shoulder made a flying leap off the down hill slope of a steep old logging road.

The other 15 or so all hit the dirt instantly. They were shot with a wide variety of cartridges, all shooting either speer hot cors, sierra gamekings, or hornady interlocks.

Powdr,
Take everybodys advise and make an elk hunt happen. Even if you don't harvest one, the experience will be well worth it.