The 6.5 Creedmoor and the 6.5-284 certainly are good for the 1000 yard shoot...the 6.5 Grendel runs out at around 800 yards - none of them are usually found in a gun that you'd happily haul arund the countryside, unless you're built like Bigfoot.
I shoot a 6.5x55SE, and it ain't no 1000yard target rifle, that's for sure.
However, make up your own mind.
tac