This is our Beretta AR-70/90 barrel, made from chrome moly alloy steel, button rifled. Machined in-house on our own CNC machines. Barrels are 100% inspected for headspace and are guaranteed to be a perfect fit in your rifle. Each barrel is test-fired with a standard round. Chambered in 5.56x45mm, 1/7 twist, parkerized finish. This is the only aftermarket barrel available in the correct 450mm (17.72") length.