AR sentry gun contraption

A group called NYC CNC has put together a video on creating a sentry contraption jig that assisted with a computer program, can automatically detect a target, then the shooter uses a string to pull the trigger. They say that everything can be made for $150, and it seems to work pretty well at the 5 meters they are shooting at with a .22 AR15. The actual mechanics of the rotors, and electrics is so far beyond my poor means to comprehend, so maybe some of our more knowledgeable readers can let us in how just how those work.

Of course, this contraption has no tactical or protective use whatsoever, never mind the liability involved if used in some kind of role akin to a “sentry”. But that doesn’t take away from the novelty of it, it is pretty neat!

They are using a string because of the various safeties involved and not wanting to get mixed up in liabilities of that.


Infantry Marine, based in the Midwest. Specifically interested in small arms history, development, and usage within the MENA region and Central Asia. To that end, I run Silah Report, a website dedicated to analyzing small arms history and news out of MENA and Central Asia.

Please feel free to get in touch with me about something I can add to a post, an error I’ve made, or if you just want to talk guns. I can be reached at


  • datimes

    At 1:37 in the video the aluminum gun mount is displayed. Where to I purchase this custom made CNC machined mount with bearings for less than $150 again?

    • simon

      you wouldn’t need anything that bad ass for it, anything that isn’t trash could be used providing it has the same movement.

      it doesn’t need to be heavy duty because ideally the recoil shouldn’t be going threw that part of the mount, the system should be set up like an artillery piece or similar to the bump fire stock system the reason its not a problem here is hes using 22lr so the mount doesn’t need to withstand much force although you would probably start getting problems with anything bigger since most guns will stop running if clamped in a vice like grip unable to react to recoil as well as the bearings getting a huge beating.

      • ostiariusalpha

        “…since most guns will stop running if clamped in a vice like grip unable to react to recoil…”
        Are you referring to just the bump fire stock? Because all autoloading firearms should operate better that fine when clamped down firmly, in fact people use them in lead sleds all the time. Even on the bumpski stock, you just clamp the stock and push/pull forward on the rest of the gun with spring tension, it’ll run quite adequately. It’s when you let the gun react too much with recoil, like limp-wristing, that you get malfunctions.

        • iksnilol

          Guns have a tendency to not cycle if the buttstock is placed against something solid like a wall or similar.

          Try it if you have the opportunity. Take your autoloader of choice, rest the butt firmly and tightly against a solid wall. And try to get it to cycle like that.

          • ostiariusalpha

            Sure, I’m up for anything. But physics says the gun is going to cycle just fine, unless it’s a blow forward operation.

          • iksnilol

            If you do, please film it. I remember seeing it a couple of years ago. Maybe it was something recoil operated or something that didn’t cycle then. Not sure.

          • ostiariusalpha

            I can see it happening on a recoil operation, but on a gas gun it will just make the cycling a bit harsher on the mechanism. Almost negligibly, in fact.

          • simon

            it was done on sons of guns with mounting a saiga or an ar15 on a atv, one of the guys holds the buttstock on a wall and it instantly jammed up the action with feeding issues.

          • ostiariusalpha

            Okay, there’s the problem. Never use “Sons of Guns” as a source of factual information. LOL!

    • micmac80

      That hog mount alone is some 300$

  • Anonymoose


    • MR

      Unless he’s trying to shoot a spider on the ceiling, he needs to work on his trigger discipline.

      • ostiariusalpha

        Robots don’t have to worry about trigger discipline. And he’s a T-100 anyways, all accidental deaths are not considered problematic.

        • iksnilol

          I know his acting is a bit stiff, but calling him a robot seems rude.

      • Don Ward

        Someone has their finger on the trigger!

        *Blows whistle*

    • DIR911911 .

      skynet thanks you for your cooperation

  • thedonn007

    I am suprised that they are using a SBR for this.

    • Mike G

      For someone who I’ve only seen dabble in firearms, and for something branded “NYC”, it is extremely odd to me….wonder if all of his paperwork is in order…

      • eriko

        He lived in NYC when he started the channel and the CNC business. He has now moved to a free state. The SBR is one he made himself (cut down the barrel) along with the suppressor that he machined himself. In addition to some nice intro to machining videos he is a shooter and like to do firearms projects.

    • DIR911911 .

      easier for the robots to get through doorways

  • iksnilol

    Weak, the mount doesn’t allow the use of a 150 round double drum.


    • Secundius

      @ iksnilol.

      Well, there’s always a Belt Feed Conversion. If the Conversion Price Shock Doesn’t Kill You First…

  • Don Ward

    *Not for use as an actual sentry.
    **Some assembly required.

  • Southpaw89

    Part of me says cool! And part of me says add some facial recognition software and an automated trigger and you have a potentially very dangerous piece of equipment, or something that could be used to keep squirrels off the bird feeder.

  • Alex Agius

    “They are using a string because of the various safeties involved and not wanting to get mixed up in liabilities of that.” – The actual reason they are using a string is the ATF would consider it a machine gun otherwise.

    • Josh

      And it would be literally such, I suppose….. Not that that makes the legal tomfoolery of that any less absurd.