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    Our Best Pistol Upper yet.  Featuring an Adjustable Midlength Gas System on an 11.5" Faxon Firearms Barrel.

    AT3 Complete Upper assemblies are Built for Accuracy and Reliability - Guaranteed.

    • Quality Where it Counts - premium components like Faxon Firearms barrels, and AT3 Tactical's handguards and uppers. Don't settle for "bargain uppers" with unknown components. 
    • Guaranteed Reliability- Carefully assembled before shipment, and backed by the AT3 Lifetime Warranty
    • Unbeatable Value - Unbeatable quality in the price range. Save up to 20% off vs purchasing the components separately.

    This fully assembled AR-15 complete upper includes:


    11.5" Faxon Firearms 1:8 4150 CMV GUNNER Barrel 

    Faxon Firearms makes some of the finest lightweight barrels in the industry, and this unique barrel is no exception.  It features a midlength gas system, keeping recoil soft while retaining a compact 11.5" length.  The 1:8 twist ensures accuracy across a wide variety of cartridges, and QPQ finish offers superior corrosion resistance.

    Wojtek Weaponry Adjustable Gas Block

    The critical component for the best possible feeding and accuracy on your new upper.  Wojtek Weaponry's adjustable gas blocks are easy to adjust to your favorite factory cartridge or handload, and use a clamp-on design to impart better accuracy better than pinned or set-screw gas blocks.

    AT3 SPEAR 12" Free Float M-LOK handguard

     AT3 Tactical SPEAR M-LOK Free Float Handguard

      Unique slim and lightweight design with M-LOK attachment points. Rock-solid 6061 aircraft aluminum handguard that withstands the harshest treatment. 5-slot M-LOK-to-Picatinny rail section included

      AT3 Tactical Billet Upper Receiver

      AT3 Tactical Billet Upper for AR15

      Precision machined from 6061-T6 aluminum, this assembled upper is sleek, with extra material around the barrel extension for superior accuracy.  It mates perfectly with our SPEAR handguard and feature M4 feedramps for reliable feeding of ammunition.

      KAK Industry Flash Can

      KAK Industry Micro Flash Can, 1/2-28 Thread

      One of the most popular muzzle devices for AR15 pistols.  The conical shape directs muzzle blast and noise directly in front of the shooter, reducing concussion for the shooter.  The Micro flash can is only 1.75 inches in length, and fits perfectly under the SPEAR handguard.


        Optional Upgrades (use the dropdown menu to select):


        AT3 Black Nitride Bolt Carrier Group

        (Only $94 - save $6 vs regular price)

        AT3 Tactical provides Top-Tier Bolt Carrier Groups with all the uppers we sell.  They feature M16-style carriers, MPI inspected bolts made from 9310 steel, and properly staked grade 8 gas key screws.


        Your choice of Standard GI or Extended-Latch Charging Handle

        (Discounted Pricing - Save $4 vs regular price)

        Quality 7075-T6 charging handles - choose between standard latch and extended latch designs.


        More info:

          This product is built-to-order in our Minnesota facility. Quality takes time - please allow up to 7 days for your order to ship.

          All AT3 upper assemblies come with a Lifetime Warranty - if you ever have an issue, let us know, and we'll make it right. It's that simple.

          Don't see the options you're looking for? Let us quote you a custom upper - contact us now.



          • Barrel Length: 11.5"
          • Total Assembly Length: 20"
          • Gas System: Midlength
          • Barrel Profile: GUNNER (Lightweight)
          • Twist Rate: 1:8
          • Barrel Steel: 4150 Chrome Moly Vanadium
          • Barrel Finish: QPQ Corrosion Resistant (Nitride)
          • Chamber: 5.56 NATO
          • Muzzle Thread: 1/2-28
          • Barrel Extension: M4
          • Diameter at Gas Block: .625"
          • Gas Block Type: Low-profile
          • Receiver Material: Billet 6061 T6

          3 reasons why AT3 Complete Uppers are better than the rest. 

          1 - Quality Where it Counts

          The single most important component of an accurate AR-15 is the barrel. AT3 uppers are built using Ballistic Advantage barrels with a Sub-MOA Accuracy Guarantee.

          But the quality doesn't stop at the barrel. Our AT3 handguard and upper work together to provide superior accuracy, meaning this upper assembly offers quality without compromises.

          Many of the "bargain" complete uppers on the market source their parts from the lowest bidder - at the expense of accuracy and reliable function. AT3 is committed to using only top-quality components in our upper assemblies.

          2 - Guaranteed Reliability

          AT3 complete uppers are assembled with strict quality controls and carefully packaged for delivery to the customer. All AT3 complete uppers offer a Lifetime Warranty - if you ever have an issue, let us know, and we'll make it right. It's that simple.

          3 - Unbeatable Value

          When you buy a complete upper, you'll save up to 20% off vs purchasing the components separately. Our complete uppers are not the cheapest on the market, but they deliver unbeatable quality in the price range. We sell direct to the customer, and cut out the middle-men, to deliver the best value in AR-15 upper assemblies.

          Have Questions About this Product?

          Ask Us Now

          Customer Reviews

          Based on 1 review
          Great product

          Everything went together easily. Haven't had a chance to shoot it yet but it functions flawlessly using snap caps.

          Thanks for sharing your experience, Michael. We work hard to meet expectations like yours, we're glad we hit the mark for you. Cheers! - AB