3D Printing a Controversy

Last month, the firearms rights nonprofit Defense Distributed used a 3-D printer to create parts of a semi-automatic AR-15 rifle. When the group was able to fire over 600 rounds from an AR-15 assembled with printed parts, controversy quickly followed — a steady flow of knee-jerk reactions and downright bad reporting about the 3-D printing of firearms came in the aftermath of the test.

Ars Technica, who broke the news, wrote that the lower receiver “contains all of the gun’s operating parts,” which is simply not true. Of the hundreds of parts needed to construct the AR-15 Distributed Defense assembled, only one was 3-D printed.

The hysteria over the potential for individuals to create homemade guns made me curious about how close we were to being able to subvert the ATF and manufacture firearms on our desktops. I decided to try to print my own AR-15 to find out.

What is a gun?

To truly understand the implications of Defense Distributed’s 3-D creation, I first investigated: What is a gun?

It turns out, the ATF’s definition of an AR-15 gun is kind of silly. Only the lower receiver — the only component that Defense Distributed printed — is, itself, considered a firearm and therefore restricted. The the rest of the gun — nearly 200 additional parts — can be shipped directly to your door from your favorite manufacturer, no questions asked.

All Defense Distributed really did was print one of over 200 parts of an AR-15. The only reason the group can claim to have printed a gun is that the part they recreated happens to be the only (arbitrarily) restricted part of the entire AR-15.

It’s important to note that Defense Distributed used a $30,000 Dimension printer to 3-D print their lower receiver. Practically, anyone with access to tools of that caliber can save effort AND time by just buying and finishing a completely legal, unrestricted “80% lower receiver” — a lower receiver with a few holes missing and, therefore, not a gun — without printing a thing.

Printing my AR-15

Just how accessible and dangerous are 3-D printed guns then? To find out, I decided to try to recreate Defense Distributed’s experiment.

First, I went to, where you can rent time on other people’s 3-D printers. I submitted the necessary files to a few local printer owners, and got the following responses (most printers did not respond):

I can create a STL from the STEP file provided. Unfortunately, It is company policy not to print gun accessories or parts for weapons unless it is for a certified and federally regulated contractor.

Another printer owner said:

The prospects of 3d Printing parts for firearms is a costly and dangerous venture. The materials do not hold up to firing a bullet and end up causing catastrophic results for the weapon and possibly injure the user. Be careful and best of luck with your project!

Fine. It seems like the MakeXYZ community is a good upstanding crowd that self-polices. So, instead I used my own 3-D printer, the most widely available consumer 3-D printer on the market.

After many hours of trying to recreate the gun part, all the consumer-grade 3-D printer was able to make was a warped, imprecise, and completely unusable AR-15 lower receiver. In the amount of time it took for the printer to try and fail just three times, I could have driven to upstate New York and legally walked out of a sporting goods store with as many AR-15′s as I could carry (New York State doesn’t require permits for long rifles, but New York City does).

The Reality

It turns out the reality of home gun making is a lot duller than the “crypto-anarchy” so vividly painted by popular press.

MakeXYZ wasn’t the impromptu arms bazaar that many feared it would be. In fact, most providers seem to be wary of anything potentially firearm related. Also, consumer 3-D printers aren’t able to print with nearly enough precision to make usable receivers.

In reality, saying you can 3-D print a gun is like 3-D printing the handlebar of a bicycle and claiming you can print bicycles.

3-D printing guns isn’t an issue — for now. But, printers will get cheaper, as they get simultaneously faster and more precise. The real issue is the fragmented, poorly-enforced firearms laws in a world where additive manufacturing is becoming a very real technology.

Over the next few years, legislators will have to think carefully about how 3-D printing will augment firearms accessibility and legislate meaningfully with that in mind. However, given the current state of firearms regulation in the US, freaking out about 3-D printed guns is like freaking out over burnt cookies when your house is on fire. Or, as Willard Foxton put it, if you can 3D print a gun at home you’re welcome to shoot me with it.