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(R) Muzzle Device, and the impressive 1:3 twist Modified Big Gunner Profile Barrel. The Faxon Sentinel is backed by Faxon's Lifetime Guarantee.Faxon Sentinel in 8.6 BLK rifles are optimized for supersonic ammunition. Use of subsonic ammunition may require adjustment to rifle for optimal performance.Specs: 7075 Billet Aluminum Receiver Set Faxon 16" 1:3 Twist Big Gunner Profile 8.6 BLK Barrel 4150 CMV, Nitrided Faxon MuzzLok(R) 8.6 BLK 3-Port Muzzle Brake Faxon G3 Aluminum Streamline M-LOK Handguard Faxon G2 Superfinished AR-10 BCG Faxon AR-10 Height Gas Block B5 Precision Collapsible Stock Faxon Trigger by Rise Armament B5 Pistol Grip Ambi Charging Handle Ambi Safety Selector Carbine-Length Gas SystemWeights & Dimensions: Weight: 9.33 lbs Length: 36" Depth: 7.5" Width: 2" ADVISORY: At the time of product launch, 8.6 BLK is not of SAAMI spec. Early production ammunition may be inconsistent or cause malfunction of firearm.