KAC Skeletonized AR Upper Receiver

When it comes to sports cars I believe the less weight the better, I believe in the same principal with my guns. I was never a fan of hanging a bunch of stuff on my AR15 other than the essentials. I’m even sporting a pencil barrel on my main AR. Other than thinner barrels, minimalist stocks, and running only iron sights how else can one shed ounces from their ARs? Knight’s Armament Company (KAC) and BoltCarrier.com have collaborated on a new stripped skeletonized lightweight AR15 upper receiver that weights in at around 5 ounces. You have to be ok with it looking like Swiss cheese however. They claim that they’ve figured out how to remove all this material without negatively affecting rigidity too. They retail for $150 over at BoltCarrier.com.

People are always looking for ways to lighten their AR-15 rifles from dimpling barrels to lightening rails and accessories. No one has been brave enough to skeletonize the upper receiver itself — until now.

We’ve developed a technique for removing material in a way that maintains the structural integrity without compromising rigidity.

Furthermore, our techniqe reduces the weight of the reciever by nearly a quarter while improving airflow and cooling.

As a side effect, this service also provides heretofore unprecedented access to the inner workings of the upper allowing for maintenance and application of lube without requiring disassembly. Whether you’re in the field or at a match, you no longer have to take apart your gun to thoroughly lube the bolt or swap out a cam pin.

Our hole pattern also matches the dimpling on Knight’s barrels to giving complete guns a coherent appearence.

Skeletonized AR Upper Receiver1
Skeletonized AR Upper Receiver rail
Skeletonized AR Upper Receiver full rifle

Ray I.

Long time gun enthusiast, archery noob, Mazda fan, Sci-Fi nerd, Whiskey drinker, online marketer and blogger. My daily firearms musings can be found over at my gun blog ArmoryBlog.com and Instagram.

Shoot me an email at ray.i@staff.thefirearmblog.com


  • Giolli Joker

    I’d like to see a photo of the other side as well.
    They’re technique looks a lot light drilling wherever possible, but maybe I’m wrong.

    Funny… using the rather uncommon word “heretofore” but mispelling “receiver”…

    • Ayan George

      Sorry — I did this in a rush. I was hoping “heretofore” would be a signal that this was a joke. -ayan

      • Giolli Joker

        Well, you got most of us, good job, indeed!
        And I learnt a new word, that’s good. 🙂

  • iksnilol

    Small question:

    If the holes allow you to lube the gun without disassembly, doesn’t that mean that dust and sand can enter the gun and mix with the lube?

    • sam

      I’d be worried about crud entry. Not that I usually roll around on the ground with firearms… I think some people do but not my department. And I can see where it would work for competitive shooters either way. Still, I’d be worried about crud entry.

    • Joshua

      Had this been real I would have believed every engineer in KAC died.

      Luckily it’s a April fools joke.

      • iksnilol

        What isn’t real? My comment or the upper?

        I am confused and I don’t want to look stupid.

        • Joshua

          It was an April fools joke KAC did, that TFB was 5 days late posting.

          So while they really milled out an upper like that, they did it as a joke and not an actual product.

          • iksnilol

            Makes sense… Damnit! I want a skeletonized AR upper now.

          • Ayan George

            Just to be clear, KAC didn’t do this.

  • Adam James Pugh

    Late article for an April Fools’ Day joke guys.

  • Uncle Dan

    I, too, would like to see the other side. If they’re serious about a super LW there’ll be no FA.

  • Zachary marrs

    5 days late guys

  • TCBA_Joe

    When it takes 5 days for TFB to cover an April Fools joke, you know how slow TFB is to get out press releases and announcements.

  • Kitsuneki

    It should have more vents IMO

  • Andrew

    If somehow this is not a joke- gas in the face and dirt in the gun come to mind. I don’t like getting maced with dirty CLP.

  • Brad Hudson

    I’m waiting for a skeletonized barrel. I’d be all in for that!!

    • JumpIf NotZero

      I had an MP5-SD with a selectively-skeletonized barrel 🙂

      • Fluffy Assaultbunny

        LOL ,
        How else you gonna drop the speed on those nuclear 115gr puppies.

      • Kivaari

        Those ports in the short SD barrel lost 400 fps and made the SD unreliable.

  • Vitsaus

    The sad part is things are so out of hand with the high speed low drag gimmick industry now that this was totally believable. Its really only a matter of time until some one actually does make this, and means it.

  • MR

    I’m all for skeletonized receivers, but they all got some holes where you don’t want holes. Mostly that lower row, as well as the mid-upper row, where the bolt carrier is going to make most of its contact.

    • MR

      Maybe just lower the middle row a bit, and eliminate the lower row.

  • Dracon1201

    Dang, you got me. I was definitely questioning KAC’s name on an upper at only $150.

  • sam

    I mean, I was thinking crud entry would be an issue, but it’s a direct gas mechanism. So every time it fires they’ll be soot, bits of metal, maybe a loose screw or two, a Slim-Jim wrapper, and some cat-litter flying back into the receiver anyway.

  • Maxcoseti


  • RICH

    I have some ‘skeletonized’ 5.56 ammunition for sale, anyone interested …??? lLMAO !

  • Core

    Does this come with a milspec silicon face shield to deflect the hot gas and powder? This is a funny one.

  • jamezb

    This reminds me of something I would like to have, I’m a big, tall guy. A M4 looks like an SBR in my hands, and a full length AR15 rifle is carbine-handy to me. I have little use for rail systems, having grown up using a handful of sling like many use a vertical foregrip. I’d love to have an extended length carbon fiber free-float tube perforated lake a 1919A4’s barrel jacket, that covered the barrel, low-rise gas block, and flash hider, making the rifle smooth and uniform forward of the upper. I realize this isn’t very practical, much less tactical, but I think that it would look cool as hell.
    (end wistful gibberish)

  • Patrick Selfridge

    Wonder if they come with dust cover?

  • bruce Cambell

    Darn.. I wanted this to go with my skeletonized mags and barrels.

  • M.Mitchell Marmel


  • CavScout

    SHOOT IT!!!