DO NOT Build A Fully Automatic Battery-launching Air Gun

There’s nothing quite like [Elliot]’s cherubic sense of wonder and maniacal laughter after he tests his fully automatic AA battery-launching air gun. That fires 600 rounds a minute. At 200 feet per second.

We need to take a minute and say [Elliot]’s gun is stupidly unsafe. He used PVC pipe to hold air pressure, so that may… explode one of these days. Also, the AA batteries coming out of the end of the barrel have the same kinetic energy as a .22 rifle bullet.

The mechanics of the gun is a simple blow forward bolt. When he pulls the trigger, the bolt – and battery – are forced forward due to air pressure. After the bolt has cleared a plug, air is allowed to flow through the bolt pushing the battery along with it. Once the pressure in the barrel is back down to normal, a spring forces the bolt back into place and the 23 round magazine loads another battery. Simple, really. [Elliot] posted some pics of his gun on the forum.

The gun is accurate to about 100 yards. It’s a very impressive piece of engineering for a bit of PVC pipe, but we don’t feel the need to copy this one. Check out the videos after the break to see this thing in action.

178 thoughts on “DO NOT Build A Fully Automatic Battery-launching Air Gun

  1. Shooting batteries is probably just a bad as shooting lead bullets / shot. Actually, a .22 round probably contains more heavy metal than a AA battery.

    Still, I could only sit through 30 seconds of the video before stopping it and wondering why he didn’t just purchase a gun. The effort is laudable even if the result is hazardous.

    – Robot

  2. To all of you ranting about how unsafe this is. Go do something dangerous with your life, get off your couch and stop whining about when others put their mind to it.

    To all of you whining about the pointlessness of it. How many hobbies out there accomplish nothing but to occupy some one’s time

    To the rest of you whining for any other reason. Read Absinthe and Flamethrowers by William Gurstelle.

    “Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure, or nothing.”
    — Helen Keller

  3. It’s a nice build minus the safety issues, I just hope he didn’t build it in New Jersey. Technically it’d be a firearm here seeing as the diameter of an AA battery is only a bit over 1/2″ at 200fps.

    “Firearm or firearms” … shall also include, without limitation, any firearm which is in the nature of an air gun or other weapon of a similar nature in which the propelling force is … compressed or other gas … and ejecting a bullet or missile smaller than three-eighths of an inch in diameter, with sufficient force to injure a person.

    1. You are lacking the key component. This is not, in any way, a firearm.

      TO be a firearm you have to have an explosive charge.

      On it’s best day, this thing would be a Destructive Device. Which it isn’t.

      What it is, is an air gun, which federal law is specifically written such as to leave them unregulated.

      1. There was a German company that built air-gun/canes around the turn of the century before last, which were eventually illegal in Germany as they could put a 10 mm steel ball through a boiler-plate, with only hand pumping.
        Dash it all, they were a lark.

  4. I love this thing. And all the follow up comments are either good for improvements or just plain funny. The Adult in me says why build something so pointless. The tin foil hat person in me says we all need to know how to build alternative weapons in case we have to rise up against our oppressors. And my inner geek says ooooooo cooooool.

  5. Why does the title remind me of Ned Beatty’s character in “1941”?
    – Do not disengage the gun carriage lock.
    – Do not place a clip of ammunition into the feed rollers.
    – Do not pull the charging handle to the rear.
    – …
    – And do not, under any circumstances, ever depress the foot trigger!

  6. Well… I’m going to stick to my coil gun, much more safe (although it’s inherently dangerous due to the fact that it’s a hacked together homemade firearm). This is awesome, but really dangerous (and questionably legal).

    1. nikescar, 2 years ago i built a paintball gun, and i spent months working on it to get it to shoot faster… but i could never get it to shoot any faster than 120 rounds per minute. Then a few days ago i rebuilt the bolt mechanize to properly accept AA batteries. The next day i take it out and test it… i notice a few problems, and after another day of working on it i think i fixed the problems… then the next day i head out and test it… the results of which you have already seen in the video above. 2 years old… 2 days worth of work and i finally get it to fire at a speed that is acceptable to me. I was very happy with the results… not only that but that is the first time i fired a fully automatic weapon of any kind that can shoot faster than 2 rounds a second. Now that the work is done, the fun can begin.

  7. Thereby proving that if you outlaw guns, then only mad scientists will have guns… wait, that isn’t how the cliche goes!

    AA would probably not be my choice of ammunition, but the device amuses me on multiple levels nonetheless.

    1. I have a low tech version. You just use a pipe and your arm. Spin the pipe real fast and let the battery fly! By the time the battery leaves the barrel, it’s move pretty damn fast. Yeah, I was a dangerous kid back when I tried that. :P

  8. I will bring up the bad math again…They “typical” AA battery has a mass of 23 grams (.023 Kg) x 200fps (60.96 mps) = 42.7 Joules. A 40grain (2.59 gram or .00259 Kg)bullet @ average (low velocity) of 1080fps (329 mps) is 140 Joules…no where near the same kinetic energy and for the last time I realize HAD has to cover their ass for liability but so many air cannons have been made without catastrophic results the “it will blow up in your face” rhetoric is getting really old. Plain and simple if you have to put a disclaimer on it you shouldn’t be publishing it anyway.

  9. I find it funny that this web site had a warning about not being negative and that all the comments are negative, etc. This article on HaD is itself negative, with no need. Apparently, the writer has some sort of delusion that he is an engineer and deems this gun unsafe by design. Go back to your Arduino and leave your ignorance off the net.

  10. +1 for laughing uncontrollably in the first video. Yeah we’ve all done it, or you’ve never done anything cool.
    +1 for the idea of shooting batteries with LEDs attached at night.
    Safe enough you pansies. Get over it. Real guns go Kaboom too sometimes.
    Sadly once you own a real gun the pneumatics just don’t hold the same awe.

  11. 80 psi to pvc scares me. I had a 3in pipe come unglued around 50psi and it sounded like a small bomb went off. Thankfully I had enough sense not to be close to it for the initial charge. A few months later “Catastrophic failure” was explained to me. Also had a small piece explode in a fire once. Think one end was clogged and the other capped. Had no idea it was in there or how it got there. That sounded like a bomb, blew sht everywhere. Thankfully no one was hit with anything. Seriously sounded like a fn real bomb, concussion wave, ear ring, echo and everything. PVC can be some bad stuff, especially at the joints. The pipe may be rated for 400psi but the glued joint may not have set right and dropped that down to 87psi.

  12. Licensed gun smith and a Conceal Carry instructor.-
    Most AA batteries are zinc-carbon based so you wouldn’t get lead poisoning, but there are a lot of other toxic components if they leak. But look it up, tons of other crap the EPA would love to have a talk with you about, just buy a gun that can deliever rounds easily at 300+ meters or a .308 or .338 that can with the right optics produce excellent groupings at 1700meters.

  13. Disgustingly stupid idea to shoot batteries containing very poisonous substances into your environment. A lot of those will be lost somewhere in the green. This has to be illegal pretty much everywhere in the world except third world countries.

    1. To the nannies bitching about the batteries and the environment: You know what? The country is tired of people telling us what to do. You’ve worn out your welcome. If you want to lecture people, get a teaching degree or run for office. Then you can get paid for being smug or sticking your nose into everybody else’s business.

  14. Good for you ukilliheal, your gun is awesome. It’s nice to see problems solved with a mechanism instead of a micro-controller.

    HaD comments are like a broken record. Things are dangerous, we get it. Careful with that Arduino, you could put an eye out with those pins.

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