I know I am late to the party and you have already placed your order, but thought I'd add my two cents anyways in case someone else comes along checking out your thread.
I purchased a Remington R-15 in .30 Remington AR (.30 RAR) last year for hunting use. Bought it for deer, antelope, pigs and coyotes. I absolutely LOVE this cartridge. It comes in 4 different factory loads from Remington and can be reloaded with any .308 cal bullets up to 165gr (maybe heavier with testing). It is basically a .450 Bushmaster case necked down to .308 caliber. It basically resembles a .30BR. There is someone that has already necked this case down to 6.5mm as well. I want one of those.
I used mine to bag my deer this past year in Colorado and it performed flawlessly. 109yards and he was dead in his tracks. Collapsed on the spot with a double-lung shot.
My rifle with Nikon:
That is a 7mm-08 on the left, a .223rem on the right and 3 different .30 RAR loads in the middle.