Geissele Super Duty MOD 1 Complete Upper Receiver Group 5.56 -14.5" P&W with Mk16 Rail - DDC

ships from our shop in 3 to 5 days (+/-)
Limited Availablility:
we get regular shipments, but not always in stock

Geissele Super Duty MOD 1 Upper Receiver Group 5.56 NATO Complete - DDC

Non-NFA pinned and welded 14.5" barrel and Mk16 Rail.

The 14.5” Mod 1 complete upper in 5.56 NATO features a DDC upper receiver mated to a unique Mk16 M-LOK rail with 14.5” Phosphated, Cold Hammer Forged Geissele, Chrome-Lined 1:7 twist barrel, with a HUXWRX muzzle device and Geissele reliability enhanced bolt carrier group.


  • Geissele Factory 14.5" Super Duty Upper Receiver Group
  • Popular DDC anodized color
  • Super Duty forged upper receiver
  • Matching dovetail connected Mk16 M-LOK rail
  • HUXWRX Flash Hider-QD 5.56 suppressor mount
  • Geissele enhanced BCG
  • Geissele CHF 14.5" barrel with Geissele pinned Super Compact Gas Block
  • Geissele military grade Airborne charging handle, in DDC
  • Steel grommets for rail QD slot
  • New Mod1 model:  08-547S

Engineered for peak performance, the Geissele Super Duty Mod1 Upper Receiver in classic DDC seamlessly integrates with your AR-15 platform. This premium upper features a Geissele 14.5" chrome-lined barrel, boasting a 1:7 twist rate for exceptional accuracy. The HUXWRX Flash Hider is pinned and welded for legal compliance and suppressor compatibility.  The mid-length gas system paired with the Super Compact Gas Block guarantees smooth operation, while the 13.5" Mk16 rail is ergonomic and has M-LOK slots for easy customization.  Geissele's quality Reliability Enhanced Bolt Carrier Group and Stressproof bolt offer improved durability and feeding reliability.

Geissele barrels are precision machined, chrome lined, and cold hammer forged. The midlength gas system is perfect for the 14.5" barrel, and includes a Geissele Super Compact Gas Block installed at the factory with both lower set screws and cross pin. This is something Geissele has been doing since 2018. Is it necessary? No, but an ounce of prevention is worth a pound of cure.

The Super Duty version of the 13.5” Super Modular Rail Mk16 mates to the upper via a center aligning tab, removing any chance of rail rotation. This rail is a variant of the 13.5” SMR MK16, currently fielded by USASOC, and one of Geissele's bestsellers and best ideas. At Charlie's, we like the way in which the upper mates to the rail, which also is a crutch to better align the rail and upper receiver. That is a good thing.

Geissele Reliability Enhanced Bolt Carrier Group

The Reliability Enhanced BCG is DLC coated in what Geissele calls "Nanocoating" and is machined from mil-spec 8620 steel, with a properly torqued and staked, chrome lined gas key. The REBCG also features extended upper rails, providing greater stability and dramatically increasing feeding reliability. The REBCG is Nanoweapon coated, and requires less oil. Geissele's Stressproof bolt is forged from exclusive Carpenter 158+ for increased durability.

The Geissele Super Duty ships with a HUXWRX Flash Hider-QD 556 pinned and welded to bring the barrel out to the legal non-NFA 16". It also serves to accept HUXWRX silencers.

The Super Duty upper also includes the DDC Airborne Charging Handle. The Mk16 rail is unique to this upper, as it has the dovetail fit to the upper. This is not a standard Geissele Mk16 rail, nor is the upper a standard Geissele upper. The two are meant to be used as one system.

The Super Duty Complete Upper from Geissele Automatics offers unmatched performance, accuracy and reliability.


LENGTH: 14.5"
COLOR: Desert Dirt Color - Geissele DDC
RECEIVER: Geissele Super Duty Upper w/ dovetail cut-out (only fits Geissele Mk16 dovetail rail)
BOLT CARRIER GROUP: Geissele Nanoweapon Reliability Enhanced BCG
BOLT: Geissele Stressproof Carpenter 158+ bolt - HPI/MPI
RAIL: 13.5" SMR MK16 with receiver dove-tail
BARREL: 14.5" Geissele Barrel, CHF, Chrome Lined, 1:7 Twist, Pin and Weld Muzzle Device
GAS SYSTEM: Mid Length
GAS BLOCK: Super Compact Gas Block
CHARGING HANDLE: Airborne Charging Handle, Military Issue DDC

HUXWRX Flash Hider-QD 556

Note: DDC color can appear from tan to beige to green in pictures. Actual colors do vary quite a bit, but for some reason, pictures accentuate the differences. There may also be variations in the finish. See the explanation of "Variations on Finish" on the Geissele site.

Pics courtesy of Geissele, Potomac Armory and Charlies Custom Clones