Geissele Super Duty MOD1 | 5.56 NATO | 11.5 in

The Geissele Super Duty MOD1 is a complete AR-15 upper chambered for .223 Rem/5.56 NATO with an 11.5-inch, chrome-lined, cold-hammer-forged barrel and a 1:7 twist rate. This assembly includes a nanoweapon-coated HUXWRX QD flash hider, a 10.5-inch Super Modular Rail MK16, and Geissele’s Reliability Enhanced Bolt Carrier Group with the Stressproof bolt. The unit uses a carbine-length gas tube and Geissele Super Compact Gas Block for a compact, reliable gas system. Typical applications include precision range training and competitive shooting where a compact, robust upper is required.

Product Specifications

• The caliber is .223 REM/5.56 NATO.
• The barrel twist is 1:7.
• The barrel length is 11.5 inches.
• The barrel is chrome-lined and cold-hammer-forged.
• The barrel finish is manganese phosphate coated.
• The muzzle device is a nanoweapon-coated HUXWRX Flash Hider-QD.
• The gas system uses a carbine-length gas tube with a Geissele Super Compact Gas Block.
• The rail is a 10.5-inch Super Modular Rail MK16 that mounts to the upper with a center-aligning tab.
• The product type is a complete upper designed to fit AR-15 platforms.
• The included bolt carrier group is the Reliability Enhanced Bolt Carrier Group.
• The bolt is a Stressproof bolt made from Carpenter 158+ material.
• The listed finish is anodized.
• The color is black.
• The sights are a flat top configuration.
• The UPC is 810081133722.

The Super Duty MOD1 complete upper brings industry-grade materials and Geissele’s engineering to an AR-15 platform in a compact package. With a durable, chrome-lined barrel and a feature set drawn from operational feedback—like the MK16 rail interface and enhanced BCG—this upper is built for repeatable function and service life under sustained use. Its configuration suits builders and shooters who prioritize rugged construction, reliable feeding, and a compact handling profile for competitive and training environments.