3D Printed Guns – 2018’s Y2K Bug

Looking at the news, you would think the release of plans for printing 3D guns like "The Liberator" was a harbinger of the apocalypse. If you have some background knowledge and experience in 3D printing and wade past the hype, you’ll come to a few conclusions that imply the level of concern is too high.

The Liberator and similar Ghost Gun 3D printable plans are nothing more than single shot “zip guns” or “Bang sticks”. While plastic zip guns like the Liberator can be made so that the firing pin is just about the only piece of metal in the gun, they are extremely bulky and far from “undetectable.” The Liberator and other 3D printed guns have very bulky and distinctive shapes and their components, even when disassembled, are very recognizable to trained personnel. Based on screen shots and what you see of TSA screening systems, I suspect screeners know the outlines of 3d printed weapons as well as their major components and are actively looking for them. These plastic guns are NOT invisible to airport scanners even though they do not set off metal detectors. “Softer” targets that do not have sophisticated scanning equipment would be more vulnerable to non-metal weapons, but there is the bulk of these zip guns to deal with; they are not easily concealed.

An additional issue is that the materials used by plastic 3D printers have a very low melting point and are not sturdy when heated or under pressure – like the temperatures and pressures generated when firing a gun. Unless you use a metal barrel in your zip gun, they do not last very long; usually one shot – often less. Many blow up, literally, on the first firing. There are some extremely dramatic examples of this self-destructive tendency online on YouTube and other sites. Sometimes your 3D printer projects crack or split for no apparent reason even when you have good equipment, good plans and experience. 3D printers are not designed to make high strength, high temperature parts; they are certainly not made to survive long when exposed to the high heat and explosively expanding gases and forces of firing a bullet. 

All 3D printers create objects by melting a filament “string” of different types of plastic and forming a part by building it up layer by layer. The plastics used in printing have a melting point of between 60°C and 150°C. The powder used as the propellant in bullets ignites at about 300°C to 350°C.  Do the math; 300°C is much greater than 150°C. What happens when you drop an ice cube into very warm water? It often cracks and partially melts immediately. If the plastic gun survives the first firing, either the barrel or the main body of the gun, or both, will likely be damaged beyond re-use.

The instructions that came with the original 2013 plans said:

Before firing a barrel, we recommend heating acetone to boiling and treating the barrel for ~30 seconds to decrease the inner diameter friction, which increases barrel life from 1 round to ~10 rounds. Note that we recommend printing multiple barrels and using each only once. Swapping the barrels is simple and fast: rotate the barrel to release the locking cam. Pull up on the barrel. If the barrel cam broke, turn the Liberator upside down to remove the debris. Then drop your new barrel in and rotate it until it locks.

So, to recap that, even after boiling the barrel in acetone (when heating nail polish remover to boiling, it tends to catch fire) , the instructions say that you should use the barrel only once. They take 1 to 4 hours to print each, by the way.  Also, the part of the barrel that locks it into place in the gun breaks often enough that you’re instructed on how to deal with that common occurrence.

I remember when I was in Junior High and High School in the 1980s, people made the same dire predictions about the publication and sale of the United States Army “TM 31-210 Improvised Munition Handbook” and The Anarchist Cookbook. Since the news and other adults made such a big deal about how horrible these books were and that they were going to single-handedly bring about the end of civilization, I of course acted like the honor student that I was and went out to my local Borders and bought both right away. They were a ridiculous waste of money and time.  

Clearly Ghost Guns, guns without serial numbers that are partially or wholly made by individuals, are a serious concern. An individual can possess a gun they make, bypassing background checks and other registration regulations. Fortunately, real gunsmithing is very hard and requires very specialized skills and equipment. The problem posed by traditional Ghost Guns was even the topic of the July 23rd episode of the CBS show, Elementary. 

Clearly “If it bleeds, it leads” is still a guiding principal in today’s news. Don’t get me wrong, there is a real danger and threat posed by plastic guns and as the technologies and materials used in 3D printing advance, it will become a more serious problem. Plastic Guns are like the Y2K scare; there were some industries that absolutely had to remediate and in many cases rip-and-replace hardware to prevent a January 1, 2000 meltdown, but this situation is overhyped, will not end civilization as we know it and the dangers posed by this use of 3D printing will be handled.