Geissele Super Duty MOD1 5.56 NATO 11.5" 1:7" CHF Chrome Lined Bbl DDC Complete Upper Receiver Group 08-544S

The Geissele Super Duty MOD1 5.56 NATO 11.5" 08-544S upper is built for hard use in short-barrel rifle or pistol configurations, whether that's close-quarters work, a suppressor host, or a build where every inch of length matters. It ships as a genuinely complete assembly, BCG and charging handle already installed, so mating it to a compatible lower is close to the last step in the build.

The 11.5" barrel is cold hammer forged from Chrome Moly Vanadium steel with a 1:7 twist and chrome lining, topped with a HUXWRX Flash Hider-QD muzzle device that's ready for suppressor attachment without needing a separate mount. A Carbine Length gas system, tuned specifically for this barrel length, keeps cycling reliable across suppressed and unsuppressed use alike, and across a wide range of ammo types and conditions.

A 10.5" MK16 Super Modular Rail mates to the upper through Geissele's center aligning tab, giving robust M-LOK compatibility for optics, lights, or IR systems without any risk of the rail working loose over time. Cycling runs through Geissele's Reliability Enhanced Bolt Carrier Group, built around the Stressproof Bolt and Nanoweapon coated for wear and corrosion resistance well past a standard finish. An Airborne Charging Handle rounds out the assembly, ambidextrous and low-profile enough to avoid snagging gear.

Finished in Geissele's Desert Dirt Color anodizing and weighing 3 lbs 8 oz, this 11.5" upper receiver is engineered for duty use and high-performance builds alike.

Key Features

• Ships complete with BCG and Airborne Charging Handle installed
• 11.5" cold hammer forged, chrome-lined barrel, 1:7 twist
• HUXWRX Flash Hider-QD muzzle device, suppressor-ready
• Carbine Length gas system tuned for an 11.5" barrel
• 10.5" MK16 Super Modular Rail via center aligning tab
• Nanoweapon-coated Reliability Enhanced BCG
• Weighs 3 lbs 8 oz
• Finished in Desert Dirt Color anodizing