AT3™ Slick Side AR-15 Upper with Black Nitride 5.56 Bolt Carrier Group

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AT3 Black Nitride Bolt Carrier Group with Slick Side Billet Upper – 8 Colors to Choose From

Get a head start on your build with the AT3 Black Nitride Bolt Carrier Group, plus the AT3 Slick Side Upper. These two components are already discounted when you buy this kit, including the full range of Cerakote finishes that we offer for the receivers. From here, you can build out your ideal upper receiver group, with a handguard, charging handle, and more.

Be sure to look out for a barrel as well, whether chambered in 5.56 or .223, .300 Blackout, or .350 Legend. These three calibers share the same 5.56 bolt face, which means the AT3 BCG can be used for a variety of builds. Plus, with the upper receiver, you get a sleek, unique look, in whatever color works best for your AR rifle.

AT3 Tactical Black Nitride Bolt Carrier Group – 5.56, .300 Blackout, and .350 Legend Compatible

Getting a high quality bolt carrier group (BCG) that runs well in your rifle is absolutely critical.  AT3 offers this BCG with a black nitride finish, which reduces friction and increases surface hardness for a lifetime of use.  The carrier itself features a full mass M16 cut for the best possible reliability in your AR-15 build.

BCG Made in the USA

The bolt itself features shot-peened 9310 steel construction, which is Magnetic Particle Inspected (MPI) to ensure there are no hidden cracks or stress points.  The bolt also has a chrome-plated firing pin, and a mil-spec o-ring extractor already installed to ensure reliable extraction of spent brass.

AT3 sources these nitride BCGs from one of the largest suppliers of bolts and carriers in the firearms industry.  When you buy a BCG from us, you’re getting a high-quality product that’s made in the USA, that’s trusted by dozens of brands and manufacturers, and we back every one with our AT3 lifetime warranty.


  • Caliber: .223/5.56, .300 Blackout, .350 Legend
  • Finish type: Black Salt Bath Nitride
  • Carrier Type: M16/Full Auto Capable (Best for AR-15)
  • Carrier Material: 8620 Gun Steel
  • Gas Key Material: 4130 Steel
  • Gas Key Screws: Grade 8
  • Bolt Material: MPI tested 9310 Steel, Shot Peened
  • Extractor Material: 4140 Steel
  • Cam Pin Material: 8620 Steel
  • Firing Pin Material: 4140 Steel, Chrome Plated
  • Mil-Spec O-Ring and Gas Rings
  • Weight: 11.5 oz.
  • Country of Origin: USA

AT3 Slick Side Billet Upper Receiver

Machined from billet aluminum, this unique slick-side upper receiver has no forward assist and includes a dust cover. It matches perfectly with AT3’s SPEAR handguards with anti-rotation features. This upper also features more material to surround your barrel extension than typical forged receivers, making it more ideal for precision. This lower matches up with mil-spec lower receivers for a secure, reliable fit.

The AT3 Slick Side Upper Receiver also comes in a wide variety of colors, ranging from classic black, Magpul-matching Flat Dark Earth, vivid Pink, and even new metallic shades like Tungsten, Titanium, and Burnt Bronze. Flat black uppers have classic hard-coat anodizing, while the other colors receive a durable Cerakote finish.


  • M4 Feedramps
  • .250 takedown pin holes
  • Low-profile brass deflector
  • Includes dust cover
  • No Forward Assist


  • Platform: AR15
  • Material: 6061-T6 billet aluminum
  • Finish
    • Black: Hardcoat Anodized
    • Flat Dark Earth: H-267 Magpul® Flat Dark Earth
    • OD Green: H-232 Magpul® OD Green
    • Gray: H-188 Magpul® Stealth Grey
    • Pink: H-224 SIG™ Pink
    • Red: H-167 USMC Red
    • Blue: H-171 NRA Blue
    • Burnt Bronze: H-148 Burnt Bronze
    • Tungsten: H-237 Tungsten
    • Titanium: H-170 Titanium
  • Compatibility: Perfect match for AT3 SPEAR Handguards, standard AR15/M16 bolt carriers, charging handles, and some other handguards.
  • Weight: 7.1 oz

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Have Questions About this Product?

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.

AT3 Lifetime Warranty Logo

All AT3 Tactical Brand Products carry a lifetime warranty against manufacturer’s defects.

This includes AT3 Red Dot SightsHandguardsIron Sights, and any other product that carries the “AT3 Tactical” or “AT3™” name. For other brands (ex. Magpul or Troy), please refer to the manufacturer’s warranty policy.

In the event that your AT3™ product becomes unusable, we will repair or replace the product at no charge to you.

If we cannot repair your product, we will replace it with a product in perfect working order of equal or better physical condition. The warranty is fully transferable, but we may require information about the original purchase to validate the authenticity of the product.

If your product is in need of warranty service, please contact AT3 Tactical to start the process

Our contact info is available here. To expedite processing, please provide your order information and description of the defect.

Please note: The AT3 Lifetime Warranty does not cover loss, theft, intentional damage or cosmetic damage that doesn’t affect the performance of the product.

Customer Reviews

Based on 9 reviews
Jon O
Solid upper

I’ve bought two of these for different AR builds. Paired with the spear handguard it’s a nice set up.

Thank you for the feedback! We're glad to hear that these uppers are holding up well and look great with the spear handguard.

Tim Kohler

Fast and easy

Kalem Watts
Slick side upper reciever with bcg

I haven’t been able to shoot yet but the fit and finish is nice. Can’t wait to take it to the range!

Thank you for leaving a review! We're glad to hear that you're satisfied with the fit and finish of our AT3™ Slick Side Upper and Black Nitride 5.56 Bolt Carrier Group. We can't wait for you to take it to the range and see how it performs for you. Happy shooting!

Great for the money!


Thank you for taking the time to leave a review! We're glad to hear that you are satisfied with your purchase and that it has been working well for you. We appreciate your feedback and are happy to provide a product that meets your expectations.

Glenn Eilers
Nice Upper

Love these uppers especially when coupled with the spear handguard. Will be my new go to for upper builds.

Thanks for the review! We're really happy to hear that you like our AT3™ Slick Side AR-15 Upper with Black Nitride 5.56 Bolt Carrier Group!