CNC Machine Chambered in .22LR ?

If you install a barrel in a CNC lathe and shoot a cartridge in it, will it make your lathe a firearm? Well, theoretically – yes (arguable), practically – not really, from the standpoint of law – probably depends on circumstances and how any particular legislation defines firearms. Anyway, folks at Serbu Firearms did exactly that. They secured a 3.2″ long .22LR barrel in the chuck and ran the tailstock (with some sort of tool installed in it) at a sufficient speed to hit the .22LR case rim and ignite the priming compound. Serbu calls this “World’s largest .22LR pistol”.

Now, this is really fun and I am sure you guys enjoyed the video as much as I did. However, besides being cool, it also reveals something very interesting.

If somebody told me about it before I saw the video, I would bet that the unsupported portion of the .22LR case head would rupture and blow half of the gases rearward. The .22LR case has a very thin case head web thickness, nothing like any centerfire cartridge. So without being fully supported by the bolt, it should not withstand the amount of pressure generated during firing. As it often happens, something obvious in theory doesn’t prove to be so in practice. As you can see from the video, the .22LR case did not fail. Although seems like it significantly bulged at the unsupported portion of the case head.

Hrachya H

Being a lifelong firearms enthusiast, Hrachya always enjoys studying design, technology and history of guns and ammunition. His knowledge of Russian allows him to translate and make Russian/Soviet/Combloc small arms related information available for the English speaking audience.
Should you need to contact him, feel free to shoot him a message at


  • Martin Grønsdal

    A person that holds a barrel with a cartridge in it, and slams the primer with a rock, becomes a weapon (lower receiver).

    Best regards,


    • Hrachya H

      No problem there if he is serialized and registered with the government …lol

      • hghgf

        The Ssn of that person is the serial number and registration lol

        • nicholsda

          Birth Certificate number does that even before getting the SSN.

      • Dracon1201

        Gives a 1940s jackbooted thugs vibe 😉

        • Juggernaut

          The ATF circa 2017?

      • wetcorps

        $200 tax stamp for giving birth when?

        • Matt Taylor

          If you are over six foot do you still need a tax stamp?

      • Ken

        The person only needs to be serialized if he is made with the intention of being sold.

  • XT6Wagon

    guessing it was primer only so they didn’t wreck the machine.

    • derpmaster

      No, the side of the machine opens (the area where he had the MSC catalog) in order to enable long pieces of feed material.

  • Cymond

    If you lean on the lathe, does that make it a SBR?
    (it’s a joke!)

  • Giolli Joker

    “As you can see from the video, the .22LR case did not fail. Although
    seems like it significantly bulged at the unsupported portion of the
    case head.”
    You either have better screen/eyes than me, or you’ve seen a different video.
    I can barely see the case head, very hard to guess its condition.

  • Dougscamo

    Will it take an M Lok?….

    • Matt Taylor

      Everything will take an M-Lok long as you machine it right. We need to find a CNC machine…

  • 1911Junkie

    As long as you don’t shoulder that CNC machine, you should be fine….right? Right?

  • Don Ward

    Clearly we need to flood the ATF with letters asking the agency whether we can now shoulder large industrial pieces of machinery.

  • Phillip Cooper

    I must REALLY need to get my eyes checked. At no point in the video did I notice any ability to see if the case ruptured or swelled.

  • Raptor Fred

    I though they were gonna shoot it with the lathe spinning???? That would have been even neato-err! 200,000rpm and smack it with a hammer.

  • Raptor Fred
  • CTM_95
  • Qoquaq En Transic

    Is that what Serbu is doing instead of working on his SU-15?