Sweet Baby Jesus, this build parameter is a godsend.
You can do that distance with a 16" barrel, in a .308 Win pattern. You'll be a Deer Slayer at 300 yards with it. Easy. A 16" gun would be highly accurate at 60o yards, easy.
Then, you go and throw out the 7mm-08. That's an 1100 yard cartridge, all day long, from a shitty gun. Let alone an accurate one.
I'd bet that you could build a 7mm-08 AR with a 18" barrel that would be 900/1000-yard accurate, with ease. No kidding. Shorten that up to a 16" barrel, lose a few fps for muzzle velocity-over-trajectory, and you'd still be banging the hell out of 800 yards without a sweat.
2-stage trigger on an AR. World of difference for accuracy. You're used to the bolt gun world, light pull single stage - that trigger is already pre-set. No take up. Any pressure you apply makes it go bang, with no take up. ARs are different. Take up the slack with the first stage, it stops. Additional pressure/poundage sets it off. 2-stage trigger in an AR is just about mandatory for accuracy or precision.
I have a 2.5lb TImney on my Rem 700, and it's just press-and-go. No take up. An animal like that, in an AR, just about doesn't exist, hence the need for a good 2-stage.