Description PSA 16″ Freedom Upper The PSA 16″ Freedom upper has stainless steel barrel chambered in 5.56 NATO, with a 1:7 twist, M4 barrel extension, and a mid-length gas system. Barrel: 4150V Chrome moly VANADIUM steel, 16″ barrel length chambered in 5.56 NATO, with a 1:7 twist, M4 barrel extension, and a carbine-length gas system. The M4 profile barrel has a gas nitride finish for accuracy and durabiltly, and is finished off with a .750″ diameter low-profile gas block, PSA 13.5″ M-Lok Lightweight Free Float Rail, and an A2 flash hider. Upper: Forged 7075-T6 A3 AR upper is hard coat anodized black for durability. Featuring M4 feedramp cuts, these upper upper receivers are made for us right here in the USA Bolt Carrier Group: Toolcraft Bolt is made of Mil-spec Carpenter 158 steel, shot peened, and mag particle inspected. Gas key is chrome lined, phosphate coated, and secured with grade 8 fasteners and staked per mil-spec. Full-auto bolt carrier is phosphate coated and chrome lined. Made in the USA. DETAILS: Gas System: Carbine Barrel Profile: M4 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 Hand guard Type: PSA 13.5″ M-Lok Lightweight Rail Bolt Steel: Mil-spec Carpenter 158 steel Bolt Carrier Profile: Full Auto Charging Handle included: No Overall Length: 24.5″ Weight: 4.0 lbs
