The 12.5" complete upper in 5.56 NATO showcases a Desert Dirt Color upper receiver seamlessly paired with a distinctive Mk16 M-LOK rail. Equipped with a Black Oxide coated, Cold Hammer Forged Geissele barrel, Chrome-Lined with a 1-7 twist, nano-coated HUXWRX Flash Hider-QD, and a robust Geissele low profile Super Compact Gas Block installed at the factory.
This is a Geissele Factory upper.
Geissele's barrel craftsmanship stands out with precision machining, chrome-lining, and cold hammer forging. The carbine length gas system perfectly complements the 12.5" barrel, incorporating a Geissele Super Compact Gas Block installed with both lower set screws and cross pin. While not absolutely essential, this approach embodies the philosophy that preventative measures are invaluable.
The innovative Mk16 rail connects to the upper receiver via a center-aligning tab, eliminating any potential rail rotation. Derived from the SMR MK16 currently utilized by USASOC, this rail represents one of Geissele's most successful design concepts. The integrated mounting system provides an additional alignment mechanism, which is undoubtedly a positive engineering feature.
The Reliability Enhanced BCG features a DLC coating Geissele calls "Nanocoating," machined from mil-spec 8620 steel with a precisely torqued and staked, chrome-lined gas key. Extended upper rails enhance stability and dramatically improve feeding reliability. The BCG requires minimal lubrication and features a cam pin crafted from advanced medical-grade H13 steel, coated with Nanoweapon for superior corrosion and wear resistance.
The Bolt Carrier Group is paired with the Geissele Stressproof Bolt, developed in collaboration with Carpenter Steel metallurgists. Crafted from Carpenter 158+ steel, the bolt offers exceptional purity and reduced impurities. Forged, not machined, the bolt's optimized grain structure provides up to five times the life of a standard mil-spec bolt. Each bolt undergoes rigorous high-pressure testing, magnetic particle inspection, and Nanoweapon coating.
The Super Duty ships with a HUXWRX Flash Hider-QD 556, compatible with HUXWRX silencers.
The upper includes the Airborne Charging Handle. The Mk16 SMR rail's unique dovetail fit ensures it's specifically designed for this upper – neither a standard Geissele Mk16 rail nor a standard upper, but a purpose-built system meant to be used as one integrated unit.
The Super Duty Complete Upper from Geissele Automatics offers unmatched performance, accuracy and reliability.
Pics courtesy of Geissele, Potomac Armory, and Charlies Custom Clones
| Specification | Details |
|---|---|
| LENGTH | 12.5" |
| CALIBER | 5.56 NATO |
| COLOR | DDC |
| RECEIVER | Geissele Super Duty Upper w/ Cam Pin cut-out |
| BOLT CARRIER GROUP | Geissele Nanoweapon Reliability Enhanced BCG |
| BOLT | Geissele Stressproof Bolt with Asymmetric Cam Pin |
| RAIL | 11.5" SMR MK16 with receiver dove-tail |
| BARREL | 12.5" Geissele Barrel, CHF, Chrome Lined, 1-7 Twist, Geissele Profile |
| GAS SYSTEM | Carbine Length |
| GAS BLOCK | Super Compact Gas Block |
| GAS PORT SIZE | .065" |
| CHARGING HANDLE | Airborne Charging Handle |
| MUZZLE | Nanoweapon coated HUXWRX Flash Hider-QD 556 |
| MPN | 08-545S |
Special note on the finish: The DDC finish is famous at Geissele, but the actual results will vary. Mostly, this is a golden sand color, but we have seen darker browns and tones of green as well. Be prepared for your lower to not match your upper, and you will be happy. We do not accept returns as defects for shades of color differences. If you are not happy with your lower receiver, do not accept it at your dealer. You may return, and pay for shipping and a small restocking fee (see our return and cancellation policy at the bottom of the website. See Geissele DDC color disclaimer
Geissele
Geissele
Geissele