Geissele Super Duty MOD1 10.3 Inch 5.56mm Complete Assembled AR-15 Upper

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Geissele Lifetime Warranty!
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Geissele Suppressor Alignment Gage

Geissele Suppressor Alignment Gage - 5.56

$76.50

Combat-Ready Geissele Engineering

The Geissele Super Duty MOD1 10.3″ Complete Upper delivers the highest level of performance for shooters who need duty-grade reliability and precision in a compact AR-15 platform. Built around a 10.3-inch cold hammer-forged chrome-lined barrel, this upper is optimized for durability, accuracy, and extreme hard use in tactical and professional environments. At the core of this upper is Geissele’s legendary Super Modular Rail MK16, providing a lightweight yet ultra-rigid mounting solution with full M-LOK compatibility for accessories. Paired with a Geissele Reliability Enhanced Bolt Carrier Group and Airborne Charging Handle, the MOD1 upper guarantees smooth cycling, superior gas management, and reduced carrier tilt for consistent, dependable operation in all conditions.

Features

  • Duty-grade components for mission-critical reliability
  • Optimized gas system for suppressed and unsuppressed use
  • Compact, maneuverable length ideal for CQB and vehicle operations
  • Precision-crafted to Geissele’s exacting standards
  • Includes Geissele Reliability Enhanced Bolt Carrier Group and Airborne Charging Handle

Components

  • Barrel: 10.3” 5.56mm NATO, cold hammer-forged, chrome-lined, manganese-phosphate coated
  • Barrel Twist: 1:7 twist rate for optimal performance with a wide range of bullet weights
  • Handguard: 9.3” Geissele Super Modular Rail MK16 (M-LOK compatible)
  • Bolt Carrier Group: Geissele Reliability Enhanced Bolt Carrier Group (REBCG), chrome-lined and precision machined
  • Charging Handle: Geissele Airborne Charging Handle (ACH) for smooth and ambidextrous operation
  • Gas System: Carbine-length with a Geissele Super Gas Block, securely pinned in place
  • Finish: Durable Type III hardcoat anodized upper receiver and rail
  • Muzzle Device: Nanoweapon®-coated HUXWRX Flash Hider- QD 556
  • Compatibility: Suppressor-ready for NFA builds
  • Made in the USA by Geissele Automatics

Specifications

  • Brand: Geissele
  • Model: Super Duty MOD1 10.3 Inch 5.56mm Complete AR-15 Upper
  • MPN: 08-543S and 08-543B
  • Fit: Mil-spec AR-15 Lower Receivers
  • Caliber: 5.56
  • Barrel Length: 10.3″
  • Handguard Rail: MLOK
  • Material: Stainless Steel and Aluminum
  • Finish: Type III Hardcoat Anodized
  • Colors: Black and Desert Dirt Color (DDC)

Products available on this page:

The AT3 Tactical store has a 90 day no-hassle return policy for products in good condition. You can view the full details of our return policy here.

If you encounter an issue or defect with a product after 90 days of your purchase, you can refer to the manufacturer for a warranty claim. Their policies are below.

Geissele Limited Lifetime Warranty

  • Geissele Automatics warrants its firearms, components, and tools against defects in materials and workmanship during the lifetime of the product.
  • Geissele Automatics does not warrant against normal wear and tear, items consumed or expended by their normal use (including springs, pins, etc.), product misuse (including criminal misuse, negligence or use under the influence of drugs or alcohol), accidental damage, or damage caused by improper handling, unapproved modifications to the product, defective or improper ammunition, or corrosion.
  • Defective accessories (e.g., scopes, suppressors, flash hiders, sights, slings, parts with glass or electronic components, etc.) may be warranted by their original manufacturers but are not covered by this warranty.

If you submit a valid claim under this Limited Lifetime Warranty, Geissele Automatics will authorize your return of the product and, at its sole discretion, will:

  1. Repair the product, including replacement of defective parts with new or refurbished parts
  2. Replace the product with a product of equal or greater value.

If Geissele Automatics decides to replace a product under this warranty, Geissele will keep the product being replaced.

You must satisfy all terms and restrictions set forth in this Limited Lifetime Warranty and obtain a Return Material Authorization before shipping any product to Geissele Automatics.

Before shipping any product to Geissele Automatics, please ensure the following:

  1. The product has not been modified, is clean and any accessories have been removed (unless otherwise instructed by a Geissele Automatics technical support agent)
  2. There is no ammunition in any product or packaging
  3. The completed Return Material Authorization form has been placed inside the packaging
  4. The Return Material Authorization number has been clearly written on the outside of the packaging.

Any failure to follow these instructions could result in your package being refused and returned to you without repairs at your expense.

To obtain service, contact Geissele Automatics at sales@geissele.com or 610-272-2060.

Disclaimer: Manufacturer’s warranty is subject to change without prior notice.

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