Bob Owens

The saddest truth in politics is that people get the leaders they deserve

No, you can’t print a gun

Written By: Bob - Jul• 29•12

I’ve noted several journalists flipping out about the “end of gun control” because of a bit of 3D printing experimentation done by a gunsmith and presumed hacker going under the amusing alias of “HaveBlue.”

Without getting to terribly detailed, HaveBlue took a CNC machining program used to build AR-15 lower receivers, and tweaked it to talk to his 3D plastic printer. Once he did so, he was able to “print” an AR lower receiver.

CNC drawing of AR-15 lower receiver

CNC drawing of AR-15 lower receiver

To the best of my knowledge, there isn’t any reason to doubt HaveBlue’s claim that he was able to attach other conventional AR-15 parts to the plastic printed lower and fire 200 rounds through it. After all, Cavalry Arms made a combination plastic lower and stock and sold it for years.

The most substantive difference between the Cav Arms lower and HaveBlue’s is that the CA guns were made by a licensed FFL, and HaveBlue’s could be theoretically made by anyone with a computer, a 3D printer, and some instructions. But that’s a far cry from a working firearm, a fact even Popular Science couldn’t help but fudge over in their misleading headline about the story.

The truth of the matter is that the lower receiver of an AR-15 is the single most irrelevant part of the firearm, and I’ve heard the gunsmiths joke that you could make a cardboard AR lower and as long as the dimensions were correct, the gun would work. The AR lower is the part that the functional moving parts of the firearm and the furniture the shooter holds latch on to, but does not have to be particularly robust.

Mark Gibbs and some others having a bit of a freakout over HaveBlue’s experiment are perhaps right to be worried about the ability to print AR-15 lowers, as the lower is the serial numbered part our government arbitrarily decided was the firearm. All other parts can be obtained without restrictions, and it theoretically could mean that the government would have no way of knowing how many of these guns exist. Also theoretically, I could fly if I held fans and flapped my arms fast enough, but that isn’t a practical reality either.

Gibbs seems to think that the ability to print other guns parts is just around the corner, and to a certain extent, he might be right. If had the equipment to print all the parts to an AR-15 rifle, they may very well be able to fit it together, load a 5.56 NATO cartridge, pull the trigger, and have the cartridge go off… most likely, along with a decent part of their head and hands.

There are parts of a firearm that can be printed with relative ease, but the all important barrel and bolt are not among them. It is these parts that are forged and or cut from the strongest steels to contain the controlled explosion of gun going off repeatedly without failure. No 3D plastic printer is capable of making such parts, turning the act of firing an entirely 3D-printed centerfire rifle into a very short game Russian roulette.  That may change in the future if metals and polymers used in 3D printing become much stronger, but that isn’t likely to happen in the near future.

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7 Comments

  1. captainfish says:

    But Mr Owens, the fact that the ignorant in the mass-media don’t know that one can’t fire a bullet from a plastic gun doesn’t mean it shouldn’t be feared and made illegal. We need laws to protect against something that could happen but never will.

    Just like we have laws to protect against speeding jello cars and laws to protect passengers in planes made out of feathers.

    This is just the evolution of consumer protection at its height. Come on Mr Owens, don’t you want to protect the children?

  2. david7134 says:

    You can get a book from Amazon on how to make your own machine gun. It is a good how to. Of course, you can also get plenty of army manuels on how to make bombs with products from your local paint store. So the information is out there and readily available. It has been there for at least 50 years that I know of. Yet we have had only a handfull of incidents if you eliminate the Muslim problem.

  3. georg felis says:

    As I recall, ATF more than once has confiscated a batch of Airsoft BB guns as “Fully-Automatic Machine Guns, because if you take the plastic lower, drill some holes, fill some holes, sand, do some cutting, and ream out some screw mounts, and mount a AR-15 barrel to the resulting mess, you *might* be able to shoot more than one bullet before the whole mess explodes in your face.

    Next, a block of wood will be determined to be an Evil Machine Gun using the same criteria.

  4. Caspian says:

    Bob
    Interesting work being done with poly barrels and steel sleeves. Not here yet but close

  5. J. Morris says:

    I would beg to differ with you on that…

    There are commercially available 3D carving machines, which “think” they are printers. Not much larger than a regular printer, it’s mesmerizing watching them “print” a golf ball, complete with dimples, out of granite or quartz crystal, or pretty much any material one chooses to print on.

    Once you combine a computer to a mini-mill ($400.), it’s open sesame; your imagination is probably the greatest limiting factor. There are programs available (free) for tracing any solid object and converting it to tool paths so that any “average joe, do-it-yourselfer” is able to replicate any object. One doesn’t have to be a computer programmer, or a skilled machinist; just follow the directions. Basically, Pandora’s box is open, the cat is out of the bag, and you can’t unring that bell; all thanks to the Internet.
    I prefer to purchase my firearms from a reputable manufacturer; I am not a reputable manufacturer. Below is a link to a tutorial demonstrating the process:

    http://www.cncguns.com/projects/1911a1frame.html

  6. rumcrook says:

    all the high tech sci fi is here aspects of this are exciting and all but with some sheet metal and a 150 dollar break from harbor freight along with a drill anyone can make an ak reciever and end up with a little diligence, with a serviceable ak-47 from a 250 dollar parts kit which are usually only missing the sheet metal stamped reciever. thats much more realistic and its happening every day, as any gun collector with his eyes open will attest.

    also new frontier is making a polymer ar lower reciever that is pretty robust for only about 125 retail complete with the trigger group and a collapsible stock just drop on your upper.

    and how many cnc machine operators out there in little shops around the U.S. have tried thier hand at knocking out a complete reciever while the boss isnt around?

  7. captainfish says:

    hmmm.. time to outlaw CNC machines?