Geissele Automatics Super Duty MOD1 5.56 NATO Complete AR-15 Upper Receiver - 13.9" Pinned - DDC - 08-546S

Elevate your AR-15 build with the Geissele Automatics Super Duty MOD1 5.56 NATO Complete Upper Receiver – a pinnacle of precision engineering designed for tactical enthusiasts and competitive shooters who demand unrelenting reliability and performance. This 13.9-inch pinned upper in Desert Dirt Color (DDC) delivers combat-proven components in a ready-to-install package, ensuring seamless integration and superior accuracy right out of the box.

Key Features

• Premium Barrel Construction: Features a 13.9-inch cold hammer-forged (CHF) barrel with chrome lining and a 1:7 twist rate, optimized for stabilizing a wide range of 5.56 NATO ammunition while maintaining a medium profile for balanced handling and heat dissipation.
• Advanced Rail System: Equipped with a 13.5-inch MK16 Super Modular Rail (SMR) featuring Geissele’s innovative center tab for rock-solid accessory mounting, allowing quick and secure attachment of optics, lights, and grips without compromising barrel harmonics.
• Reliability-Enhanced BCG: Includes Geissele’s Nanoweapon®-coated bolt carrier group with a Stressproof® bolt and asymmetric cam pin, reducing friction and wear for smoother operation and extended service life in demanding conditions.
• Optimized Gas System: Mid-length gas system with a super compact gas block and precisely tuned .076-inch port size to minimize recoil and ensure consistent cycling, even under suppressed fire.
• High-Quality Muzzle Device: Factory-installed HUXWRX Flash Hider (QD 556) with Nanoweapon® coating for reduced flash signature and quick suppressor attachment, enhancing low-light performance and versatility.
• Ergonomic Charging Handle: Airborne Charging Handle (ACH®) for ambidextrous operation, making reloads faster and more intuitive during high-stress scenarios.

Technical Specifications

• Caliber: 5.56 NATO
• Barrel Length: 13.9 inches (pinned and welded for 16-inch legal compliance)
• Barrel Finish: Manganese phosphate
• Barrel Profile: Geissele tapered medium contour
• Twist Rate: 1:7 RH
• Gas System: Mid-length
• Receiver Material: Forged 7075-T6 aluminum with Super Duty enhancements
• Overall Length: Approximately 23.25 inches
• Weight: 67 ounces
• Color: Desert Dirt Color (DDC) for tactical camouflage
• Includes: Complete BCG, charging handle, and all necessary hardware

Why Choose the Super Duty MOD1 Upper?

This upper addresses common AR-15 pain points like inconsistent reliability and suboptimal ergonomics by incorporating Geissele’s battle-tested innovations. The pinned 13.9-inch configuration offers the maneuverability of a shorter barrel without legal hurdles, ideal for home defense or close-quarters training. Its robust construction withstands extreme abuse, while the tuned gas system reduces felt recoil by up to 20% compared to standard setups, allowing faster follow-up shots. Whether you’re customizing a duty rifle or enhancing a personal build, this upper provides unmatched durability and precision, backed by Geissele’s reputation for excellence in firearms components.

Ready to upgrade your AR-15 with professional-grade performance? Secure the Geissele Super Duty MOD1 upper today and experience the difference in accuracy, reliability, and control that top-tier engineering delivers.

Frequently Asked Questions

Q: Is this upper compatible with standard AR-15 lowers?
A: Yes, it mates perfectly with mil-spec AR-15 lower receivers, ensuring drop-in compatibility for most builds.

Q: What does ‘pinned’ mean for the barrel?
A: The muzzle device is pinned and welded to extend the effective barrel length to 16 inches, complying with federal regulations while preserving the compact 13.9-inch profile.

Q: Can I use a suppressor with this upper?
A: Absolutely – the included HUXWRX flash hider features quick-detach threads, making it suppressor-ready for enhanced versatility.