Description PSA 16″ M4 Carbine Upper The PSA 16″ M4 Carbine upper is chambered in 5.56 NATO, with a barrel with a 1:7 twist, M4 barrel extension, and a carbine-length gas system. The M4 profile barrel is finished with Phosphate. Barrel is finished off with a .750″ diameter low-profile gas block, PSA 13.5″ Lightweight M-Lok Free Float Rail and an A2 flash hider. The upper is a forged 7075-T6 A3 AR and hard coated anodized black for durability. Featuring M4 feed ramp cuts, these upper receivers are made for us right here in the USA. Bolt Carrier Group: For AR15 and M16 rifles and carbines. Bolt is made of shot-peened, Mil-spec Carpenter 158® steel. Gas key is secured with grade 8 fasteners and staked. DETAILS: Barrel Length: 16″ Gas System: Carbine-length Barrel Profile: M4 Barrel Steel: Chrome-Moly Vanadium Barrel Finish: Phosphate 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 Hand guard Type: PSA 13.5″ M-Lok Lightweight Rail Bolt Carrier Group Included: Yes Bolt Steel: Carpenter 158 Bolt Carrier Profile: Full-auto Charging Handle Included: Yes Overall Length: 24.5″ Stock photos used and may not represent actual item. Please read description.
