Windham Weaponry has had many requests for a Heavy Barreled version of our popular SRC Upper, so this complete Upper Assembly has been developed. The SRC Heavy Barrel – a straight turned design .745″ in diameter forward of the gas block – is chrome lined and machined from 4150 Chrome Moly Vanadium 11595E Steel – rifled 1 x 9” Right Hand twist. It includes an A2 Flash Hider and Mil Std 1913 Railed Gas Block with Sling Swivel and Bayonet Lug. M4 dual heat shield Handguards complete the barrel. The machined aluminum flat top Upper Receiver is complete with Bolt Carrier Assembly, Charging Handle, Forward Assist, and Ejection Port Cover.