Bonded bullets will do much more of what you saw in your 200 yard runner deer.
Elk are tougher in some senses. But they’re not hard to kill with vital shots. Their vitals are only protected by 4-6” of meat.
Rodeos with tough elk happen when you miss vitals. It will make your 200 yard deer chase look extremely mild. Pick the thing that helps you hit the vitals.
And one option is you don’t need to love away from Creed. You seem to be doing well with it. Keep yourself under 600 yards and you’re gold.