In my opinion, the 6.5 Grendel isn't a long range hunter in any type of hunting from prairie dogs to deer.
What it is is a great shooting mid range AR cartridge, with great shooting factory loaded ammunition from Hornady that makes the 6.5 Grendel a top contender for "best AR-15 cartridge" honors.
I bought the 6.8SPC years ago and was disappointed. I had in my head I was going to be able to buck Texas Panhandle winds and hit coyotes at 500 yards. Didn't happen. Sold the rifle.
When the 6.5 Grendel was introduced i became interested in the "long range AR-15" idea again and ordered a JP.
I received the rifle, mounted a night force SHV 4-16 F1.
I knew i was going to love this rifle/cartridge based on .5 moa groups at 200 yards.
My first opportunity with the rifle was a 80 pound pig running down the 2 track road. I put a Hornady up him and he went down instantly.
Since then I have shot several pigs in the 250 to 350 yard range all neck shots and the kills have been instant. Coyotes as far as 300.
With all that said, a quality built 6.5 Grendel with the new Armageddon Gear Revolution trigger, on a calm day, is capable of 500 yard coyote kills and capable of 3-400 yard pig kills on 150 pounders and im sure the cartridge is capable of ethical white tail kills at 300 yards but that hardly makes the cartridge a "long range hunter" for most members of this site.
Ethically speaking, I'm looking for long range coyote shot's or 5-600 yard speed goat shots, im using either my 6.5 or 6 Creedmoor. If I'm wanting to take 500 yard deer/elk shots, I'm using my 7SAUM. For ethical elk shots past 600 yards, its my 300NM.
I love my 6.5 Grendel and wouldn't think of carrying anything else in the AR-15 frame. With that said, i know its limitations and always got one of my Creeds with me.