This is no help on making your decision, but heres a vid of the 6.5 Creedmoore getting stretched out a bit you might find interesting. Conditions were perfect and Wayne had been hitting everything at the range at similar distances from the same prone position. Probably the outer limit for this round on elk (129gr SST).
For those that follow Waynes writing, you know that he is far from a long range hunting enthusiast. His preference leans more towards a lever gun at 100 yards.
That said, he is open minded and has shared a few other camps with us using our equipment. Also a heck of a nice guy and can really shoot with that darn sling.
This hunt he was getting some real world info on Hornadys ammo and the caliber. The rifle is actually a Magnum Research wearing our scope and stock. It was a tack driver with the factory ammo.
Clicking on the title will take to youtube where it can be viewed larger.
YouTube - Greybull Precision with Wayne van Zwoll Elk & Coyote