Geissele Automatics Super Duty MOD1 Complete AR-15 Upper Receiver - 5.56 - 16"

The Geissele Automatics Super Duty MOD1 Complete AR-15 Upper Receiver in 5.56 NATO pairs a 16" cold hammer forged, chrome-lined barrel with Geissele's Reliability Enhanced bolt carrier group and a suppressor-ready HUXWRX Flash Hider-QD.

Features:

• 16" cold hammer forged, chrome-lined barrel, 1:7 twist
• Geissele-length gas system with Geissele Super Compact Gas Block
• HUXWRX Flash Hider-QD, suppressor-ready
• 15" 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 15" SMR MK16 handguard's center-tab mounting keeps the rail from rotating under load.

At 16", this barrel already meets the legal rifle minimum, so there's no NFA consideration — just add a lower receiver and this upper is ready to run.

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.