TacFire's AR-300 Unassembled pistol build kit includes : Black parkerized barrel with a 1:7 twist rate, 5/8x24 spiral fluted Krink style frowarder muzzle device Slim M-Lok free-float handguard; 7075-T6 billet aluminum stripped upper 5.56 bolt carrier group Mil-Spec charging handle, dust cover, forward assist, heavy buffer, pistol length gas tube, low profile gas block complete pistol buffer tube, A2 black pistol grip, and lower parts kits all made in the USA Steel/Aluminum Finish - Black Parkerized AR-Style