Quote Originally Posted by WinnieTheBoom View Post
6.5 Grendel is an excellent round. I used to have an AR chambered in it. Was a ton of fun out to 600 yards or so, but anything beyond that and the conditions really needed to be ideal for any type of consistency. 6mm BR would very well suited for 1000 yards, as would the 6mm Creedmoor, though like you said, you may run into issues with mag feeding and they will both put you over that 30 grain threshold.

Otherwise, maybe look into a .22-250? Something in the 6mm family would definitely be my preference, though it sounds like you have an idea of what might suit your needs.
unfortunately none of those will chamber in an AR-15. You would have to step up to an ar-10.

I have a 6mm ar turbo which is a Grendel necked down to 6mm. It shoots 105 bergers over 2800 fps.

You can buy a savage in 6.5 creedmoor cheaper than you can buy my 6mm upper.