Geissele Super Duty MOD1 Complete Upper, 5.56 NATO, 14.5″

The Geissele Automatics Super Duty MOD1 Complete Upper is a factory-built AR-15 upper assembly chambered in .223 REM/5.56 NATO with a 14.5" threaded barrel. This complete upper pairs a chrome-lined CHF barrel and Geissele’s Super Modular Rail MK16 with a Reliability Enhanced BCG for a durable, duty-oriented assembly. The muzzle device is installed and the barrel is pinned to provide a 16" overall length.

Key Specifications

• Chambered in .223 REM/5.56 NATO for standard AR-15 5.56 NATO compatibility.
• The barrel measures 14.5" (pinned; 16" overall length) as supplied.
• The barrel uses a 1-7 twist for stability with a wide range of projectiles.
• The barrel is a cold hammer-forged, chrome-lined contour with manganese phosphate coating.
• Equipped with a HUXWRX Flash Hider-QD (Nanoweapon coated) muzzle device.
• Features a carbine-length gas system with the Geissele Super Compact Gas Block installed.
• Includes a 13.5" Super Modular Rail MK16 (M-LOK) that indexes to the upper to prevent rotation.
• Includes the Geissele Reliability Enhanced Bolt Carrier Group with Nanoweapon coating and chrome-lined gas key.
• Uses the Geissele Stressproof Bolt (Carpenter 158+) for enhanced durability and fatigue resistance.
• Finish and color are Anodized, Black and the handguard is M-LOK compatible.

This complete upper assembles Geissele's high-end features into a ready-to-install AR-15 upper that emphasizes reliability, component longevity, and system compatibility. Its combination of a CHF chrome-lined barrel, robust rail interface, and enhanced BCG makes it suitable for demanding operational use or precision-focused builds where component quality and repeatable performance matter.