Geissele Super Duty Mod 1 Upper Receiver Group 5.56 NATO 16" – AR-15 Compatible

The Geissele Super Duty Mod 1 Upper Receiver Group delivers a complete, ready-to-install 5.56 NATO upper for AR-15 pattern lowers. This 16-inch configuration features a mid-length gas system and Geissele's proprietary barrel profile, engineered for consistent accuracy across extended shooting sessions. The complete assembly includes a forged upper receiver, cold hammer-forged barrel, and Geissele's Super Modular Rail with M-LOK attachment points.

Machined from 7075-T6 aluminum with a black finish, the upper receiver is built to military specifications with M4 feed ramps. The barrel features a 1:7 twist rate for stabilizing heavier projectiles and includes a pinned low-profile gas block. Assembly arrives fully headspaced and test-fired, requiring only attachment to a mil-spec lower receiver. The rail system provides uninterrupted top rail for optics mounting and M-LOK slots at 3, 6, and 9 o'clock positions.

• Caliber: 5.56 NATO / .223 Wylde
• Type: Complete Upper Receiver Group
• Compatible Lower: Mil-spec AR-15
• Barrel Length: 16 inches
• Material: 7075-T6 aluminum receiver, cold hammer-forged barrel
• Finish: Black
• Includes: Upper receiver, barrel, gas system, handguard, charging handle, bolt carrier group
• Installation: Requires only attachment to mil-spec lower receiver; no gunsmithing required