Brand: Geissele Automatics
Model: Super Duty Mod1
Caliber: 5.56 NATO
Platform: AR-15
Barrel: 13.9" CHF, Parkerized, Chrome Lined
Color: Desert Dirt
Finish: Anodized
Gas System: Mid-Length
Muzzle Device: HUXWRX QD Flash Hider Pinned and Welded
Muzzle Thread: 1/2-28
Twist: 1:7
Receiver: A3 Flattop
Handguard: 12.9" SMR Mk16
Attachment Style: M-Lok
BCG: Nanoweapon Reliability Enhanced BCG
Charging Handle: Airborne Charging Handle
Weight: 4.187 lbs

Features

The Geissele Super Duty MOD1 Upper delivers cutting-edge performance and reliability in a next-generation AR-15 platform. At its core is the Super Modular Rail MK16, securely mounted with a center-aligning tab to prevent rotation—a combat-proven design currently fielded by USASOC.

Included is the Reliability Enhanced Bolt Carrier Group, coated in Nanoweapon for extreme wear and corrosion resistance. It features a chrome-lined, properly staked gas key, H13 medical-grade steel cam pin, and extended upper rails for smoother cycling. The BCG houses the Geissele Stressproof Bolt, forged from Carpenter 158+ steel developed in collaboration with Carpenter Steel for superior strength, fatigue resistance, and up to 5x the lifespan of a standard bolt. Each bolt is high-pressure tested, MPI-inspected, and coated for durability.

Combining advanced materials, engineering, and combat-proven design, the Super Duty MOD1 Upper is built for those who demand unmatched accuracy, dependability, and performance.

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Shipping Restrictions

It is the customer’s responsibility for understanding state laws regarding all purchases made. For a comprehensive list of all Shipping Restrictions, please refer to our Shipping Restrictions By State Page found Here.

All NFA Rules Apply

These items are controlled by the U.S. Government and authorized for export only to the country of ultimate destination for use by the ultimate consignee or end-user(s) herein identified. They may not be resold, transferred, or otherwise disposed of, to any other country or to any person other than the authorized ultimate consignee or end-user(s), either in their original form or after being incorporated into other items, without first obtaining approval from the U.S. government or as otherwise authorized by U.S. law and regulations.

Local Law Compliance

Certain firearm parts and accessories, including AR-style upper receivers, are subject to complex and frequently changing federal, state, and local laws and regulations. While an upper receiver may be lawfully sold and shipped as a component, the legality of possessing, assembling, configuring, or using an upper receiver in certain states (e.g., California, Washington State) and localities depends on how it is assembled, combined with other components, and ultimately used. You are solely responsible for ensuring that any assembly, configuration, possession, or use complies with all federal, state, and local laws, including any so-called “assault weapon” bans and short-barreled rifle restrictions. We do not provide legal advice and are not responsible for unlawful configurations or uses.