LWRC's ICDI .350 Upper allows you to tap into the power of one of the most popular straight-wall cartridges on the market. It utilizes LWRC's direct impingement operating systems with a keyless bolt carrier design. The 16-inch barrel features button cut rifling and is NICORR-Treated for superior resistance to weathering and corrosion. The barrel is topped with 9/16x24" threads for muzzle devices and suppressors. Other features include a modular one-piece free floating forend, a MONOFORGE upper receiver, a carbine length action spring, and an ambidextrous charging handle. Features of the LWRC ICDI .350 Upper: LWRCI Direct Impingement Operating System with LWRCI Keyless Bolt Carrier DesignLWRCI BUTTON CUT NICORR-TREATED BARREL - 1:16 Twist RateLWRCI THREAD PROTECTOR 9/16 x 24 TPILWRCI MODULAR ONE-PIECE FREE-FLOAT FOREND LWRCI MONOFORGE UPPER RECEIVERLWRCI AMBIDEXTROUS CHARGING HANDLEC PRODUCTS DURA-MAG 5RD STAINLESS STEEL MAGAZINEH2 BUFFERCARBINE LENGTH ACTION SPRING LWRC International LWRC ICDI Direct Impingement .350 Legend 16" 1:16" 9/16x24" Bbl Tungsten Grey Complete Upper Receiver ICDIU35TG16L