Geissele Automatics Super Duty MOD1 Complete AR-15 Upper Receiver - 5.56 - 12.5" - DDC

The Geissele Automatics Super Duty MOD1 Complete AR-15 Upper Receiver in 5.56 NATO pairs a 12.5" cold hammer forged, chrome-lined barrel with Geissele's Reliability Enhanced bolt carrier group and a suppressor-ready HUXWRX Flash Hider-QD.

Features:

• 12.5" cold hammer forged, chrome-lined barrel, 1:7 twist
• Carbine-length gas system with Geissele Super Compact Gas Block
• HUXWRX Flash Hider-QD, suppressor-ready
• 10.5" Geissele SMR MK16 free-float M-LOK handguard, center-tab mated
• Geissele Reliability Enhanced bolt carrier group, Nanoweapon coated
• Geissele Stressproof bolt, Carpenter 158+, HPT and MPI tested
• Geissele Airborne charging handle
• Super Duty upper receiver with cam pin cutout

The Nanoweapon-coated Reliability Enhanced BCG pairs a staked gas key with an advanced-steel cam pin for improved feeding, while the Stressproof bolt is forged from Carpenter 158+ and HPT/MPI tested. The 10.5" SMR MK16 handguard's center-tab mounting keeps the rail from rotating under load.

Because this 12.5" barrel measures under 16", this complete upper is intended only for an AR pistol or a legally registered short-barreled rifle — attaching it to a standard rifle lower without the correct configuration violates federal law. This model wears Geissele's Desert Dirt Color (DDC) finish, which varies in shade batch to batch by design and isn't intended to color-match.

Geissele Automatics built its reputation on the Hi-Speed National Match trigger, later adopted by U.S. Special Operations for a select-fire variant, and now applies that same quality control to complete upper receivers for warfighters, competitors, and civilian shooters alike.