Introducing the Faxon Sentinel Pistol Threaded Barrel with Pistol Brace. The Sentinel 8.6 BLK, part of Faxon's Summit Line of firearms, boasts a billet aluminum receiver set, G3 Aluminum Streamline M-LOK Handguard, new 8.6 BLK MuzzLok Muzzle Device, and the impressive 1:3 twist Modified Big Gunner Profile Barrel. The Faxon Sentinel is backed by Faxon's Lifetime Guarantee. Features1:3 Twist Big Gunner Profile 8.6 BLK BarrelFaxon MuzzLok 8.6 BLK 3-Port Muzzle BrakeFaxon G3 Aluminum Streamline M-LOK HandguardFaxon G2 Superfinished AR-10 BCGFaxon AR-10 Height Gas BlockHiperfire EDTDM Single Stage TriggerB5 Pistol GripAmbi Charging HandleAmbi Safety SelectorPistol-Length Gas System Note: Faxon Sentinel in 8.6 BLK rifles are optimized for supersonic ammunition. Use of subsonic ammunition may require adjustment to rifle for optimal performance.