Ruger SR-556UFB Upper Fixed Barrel Receiver Assembly

Standard model 5.56MM with threaded-on flash suppressor. Overall length is 25.50 inches; barrel length is 16.12 inches with a weight of 5.73 pounds. Features a black anodized aluminum finish, folding sights, three 30 round magazines, rail covers, sight tool, soft case, manual and lock. Barrels are heavy contour (.850" under the hand guard), chrome lined, cold hammer forged 41V45 steel. Twist rate is 1 in 9, exterior barrel and gas block finish is Manganese Phosphate. Piston, regulator and gas block interior are chrome plated. Barrel threads are ½ inch-28 on 5.56MM. Flash suppressors without flats can be removed with a Torx T60 bit. Back up iron sights are Troy Folding Battle sights. Quad rail by Troy. Barrel is not free-floated; the system is pinned together and functions like a monolithic upper. Transfer rod is not user accessible.