The 5.56 Midlength Base 16" Upper is a standard mil-spec upper that incorporates the patented Adams Arms technology and the m4 style handguards. The midlength piston system will give you the benefits of a longer forearm by giving the user a longer, more ergonomic grip, a longer sight radius between the front and the rear sight for quicker sight acquisition and less felt recoil. The piston system parts and the barrel have been treated with our salt nitride Meloniting process making them harder and more corrosive resistant than hard chrome. With the patented Adams Arms piston system, you'll have an upper that will run cleaner, cooler, and longer than any other AR upper you own.
Upper Receiver: A4 Flat-Top, Forged
Barrel Length: 16"
Barrel Contour: Government
Barrel Material: 4150 Chrome Moly Vanadium Steel
Muzzle Thread Pattern: 1/2"-28
Chrome Lined: No
Barrel Finish: QPQ Melonite / Black Nitride
Twist Rate: 1 in 7"
Chamber: 5.56x45mm NATO
M4 Feed Ramps: Yes
Bolt Carrier: 1-Piece w/Integral Piston Strike Face
Muzzle Device: A2 Flash Hider
Gas System Length: Mid, Short Stroke Piston Operated
Gas Block Diameter: 0.750"
Handguard: 2-Piece Polymer, Mid-Length
Sights: None, Single Rail Gas Block
Weight: 4.387 lbs