Geissele Automatics Super Duty MOD1 Complete Upper Features The Geissele Automatics Super Duty MOD1 barrel is cold hammer forged and chrome lined with a 1:7 twist precision machined at Geissele s North Wales Pennsylvania facility using the highest quality materials available. A Manganese Phosphate coating protects the barrel while the HuxWrx Flash Hider-QD muzzle device itself Nanoweapon coated reduces flash signature and adds corrosion resistance at the muzzle. The carbine length gas system pairs with a Super Compact Gas Block featuring a bomb proof installation ensuring reliable cycling even in extreme operating conditions. A Geissele Airborne Charging Handle rounds out the controls giving the shooter a fast positive manipulation point under stress. The Super Modular Rail MK16 M-LOK handguard mates to the upper through a center aligning tab that eliminates any chance of rail rotation the same rail variant fielded by USASOC operators who rely on it daily. Inside the Nanoweapon coated Reliability Enhanced Bolt Carrier Group features a properly torqued and staked chrome lined gas key along with a cam pin machined from H13 medical grade steel for corrosion and wear resistance. The Geissele Stressproof Bolt is forged rather than machined from barstock developed with Carpenter Steel metallurgists from Carpenter 158+ material to deliver up to five times the fatigue life of a mil-spec bolt. Every bolt is rigorously inspected high pressure tested and magnetic particle inspected before coating giving builders and duty users alike a true next generation upper for the AR-15 platform. Geissele Automatics Super Duty MOD1 Complete Upper Specifications Manufacturer: Geissele Automatics Model: Super Duty MOD1 Complete Upper Type: Complete Upper Receiver Caliber: 5.56 Barrel Length: 12.5 Twist Rate: 1:7 Barrel Description: Cold Hammer Forged Chrome Lined Muzzle Device: HuxWrx Flash Hider-QD Handguard: Super Modular Rail MK16 M-LOK Charging Handle: Geissele Airborne Bolt Carrier Group: Nanoweapon Reliability Enhanced BCG Gas System: Carbine Length Color: Desert Dirt Color Finish: Anodized Compatible Hosts: AR-15 Available At: GrabAGun