The Geissele Super Duty MOD1 Upper features the latest in weapon technology available exclusively from Geissele Automatics. This complete upper chambered in 5.56mm features a nanoweapon-coated HUXWRX Flash Hider-QD muzzle device mounted to a Manganese Phosphate coated, CHF, Chrome Lined barrel. Geissele barrels are precision machined and cold hammer forged utilizing the highest quality materials at a state of the art facility in North Wales, PA. The Geissele length gas system and Geissele Super Compact Gas Block with bomb-proof installation ensures reliability and optimal performance in extreme conditions.Included is a Super Modular Rail MK16 that mates to the upper via a center aligning tab removing any chance of rail rotation. This rail is a variant of the SMR MK16, currently fielded by USASOC and renowned by operators for their performance and comfort. Also included is the Geissele Reliability Enhanced Bolt Carrier Group. This Nanoweapon coated BCG features a properly torqued and...