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    Uncompromising quality meets unbeatable value. The AT3 Tactical FF-KM Complete AR-15 Upper.

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

    • Quality Where it Counts - premium components like Ballistic Advantage barrels, Aero Uppers, and AT3 handguards. Don't settle for "bargain uppers" with unknown components. 
    • Guaranteed Reliability- Test-fired before shipment to assure proper function, 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:


    16" Ballistic Advantage 1:7 4150 CMV M4 Nitride Barrel (with low profile gas block & carbine gas tube)

    Ballistic Advantage Modern Series barrels feature precision-machined 4150 CMV steel, durable QPQ (Nitride) coating, and a Sub-MOA accuracy guarantee.


    AT3 PROMOD-K Free Float Keymod handguard (choose length with dropdown menu)

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


      Aero Precision 7075 T-6 Upper Receiver

      Forged from 7075-T6 aluminum, this assembled upper is precision machined to mil- spec M16/M4 specifications and features M4 feedramps.


      Your choice of 3 different muzzle devices (choose type with dropdown menu)


      Learn more about these muzzle devices: A2 Flash HiderTactical CompensatorCombat Flash Hider


        Optional Upgrades (use the dropdown menu to select):


        AT3 Bolt Carrier Group - Phosphate or Nitride Finish

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

        AT3 Tactical partnered with the best BCG manufacturer in the industry - Toolcraft Inc - to produce these Top-Tier Bolt Carrier Groups.  They feature M16-style carriers, MPI/HPT inspected bolts, 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: 16"
          • Total Assembly Length: 24.5"
          • Gas System: Carbine
          • Barrel Profile: M4 profile
          • Twist Rate: 1:7
          • 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: .750"
          • Gas Block Type: Low-profile
          • Receiver Material: Forged 7075 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. From the industry-leading Aero Upper to the precision machined AT3 handguard and muzzle device, 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, test-fired before shipment, 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 2 reviews
          Great quality, Fast Shipping @ Excellent Customer Service

          Purchased the complete upper, product arrived fast and free shipping.
          Fit and finish is excellent, paired up with both Spikes and Stag lowers.
          Thank you William for spending some time on the phone going over some additional parts.
          Thank you Zac for going over the upgraded barrel options.
          Will be ordering from them again on future builds.

          Thank you guys !

          We are glad to hear that you are pleased with you order and the experience with AT3.
          Great buy and Service

          Working on my first build.
          Fit, finish and quality seem top notch.
          I've not finished the lower yet, but I will update after testing.
          3 calls to Zac was like talking to an old friend.
          Fast shipping and outstanding service.
          Will be buying from these folks again.

          Happy to hear that you're pleased with the end product and look forward to helping you with all future orders.