If you're looking to build something on an ar15 platform and want the absolute best semiautomatic tactical rifle upper, consider building around this pof-usa minuteman upper.The patriot ordnance factory minuteman provides the end user with some of the most impressive innovations in the industry, from the 4150 nitride-treated steel barrel with three-pronged flash hider to the strike eagle ambidextrous charging handle that is built for speed & comfort.This complete minuteman 16.5" upper receiver assembly is chambered for 5.56x45mm nato, e squared chamber and utilizes semiautomatic direct impingement technology.It features a renegade rail that's m-lok compatible.It also has four integrated quick-detach sling mounts.This milspec upper receiver will make your build something special.Receiver Finish: Patriot BrownCaliber: 5.56x45mm NATOSights: None, Optic ReadyBarrel Length: 16.50"Barrel Material: 4150 Chrome Moly Vanadium SteelBarrel Finish: Black NitrideHandguards: 14.50" M-LOKHandguard Finish: Patriot BrownBarrel Length Range: 16" to 16.99"