Criterion for the barrel. I have 4 of them for ARs and all are shooters. My 308 is a 18” mid. Very happy with it. 2 16” lightweights in 223 Wylde and a 20” in 223 Wylde. Very accurate.
I've heard good things about criterion barrels. How "accurate" is your 308? To be exact... I have been thinking about turning my AR10 308 into a 6.5 creedmoor. Might think about criterion when that happens...