**This Upper Does Not Include BCG or Charging Handle**   Specifications: Barrel Length: 10.5in Gas System: Carbine Barrel Profile: A2 Barrel Steel: 4150 Chrome-Moly Vanadium Barrel Finish: Nitride Chrome Lining: None Muzzle Thread: 1/2-28 Chamber: 5.56 NATO Twist Rate: 1:7 Barrel Extension: M4 Diameter at Gas Block: .750 Gas Block Type: Low-profile Muzzle Device: A2 Flash Hider Receiver Material: Forged 7075 T6 Receiver Type: M4 Handguard Type: WORKHORSE® 9.5in M-Lok® Free Float Rail Overall Length: 18.5in Barrel: Rosco Manufacturing 10.5in 4150V Chrome Moly Vanadium steel barrel, chambered in 5.56 NATO, with a 1:7 twist, M4 barrel extension, and a Mid-length gas system. The barrel is finished with a .750" diameter low-profile gas block, WORKHORSE® 9.5in M-Lok Free Float Rail, and an A2 flash hider.