Our 10.5” .300 AAC Blackout barrels are black nitride coated and made from 4150V with 5/8×24 threads suitable for any .308 flash hider/muzzle breaks. They come with a 1/7 twist and with the right ammo and shooter will hold tight groups. Perfect for any 300 BLK SBR or pistol build and also sold as a complete side charging upper.