How Hard Is It to Make a 3D-Printed 'Ghost Gun?'

Once police released details on the arrest of the suspected shooter of UnitedHealthcare CEO Brian Thompson, internet sleuths identified the weapon used as a Chairmanwon V1, a version of a popular partially 3D-printed Glock-based design called the FMDA (“Free Men Don’t Ask”) 19.2.

Because the suspected murder weapon employs parts that are usually 3D printed, it was assembled without creating a serial number that is registered with the government for tracking, which makes it a so-called “ghost gun.” The government's term for these guns is Privately Made Firearm (PMF).

The Chairmanwon looks like a Glock, but is made with a combination of parts that are sourced from a 3D printer to create the lower part of the gun, called the frame, with a commercially available steel barrel. The Bureau of Alcohol, Tobacco, and Firearms defines the frame as the part of a handgun that provides housing or structure for the sear or equivalent – that part that holds back the hammer, striker, bolt, or similar component prior to firing.

The ATF describes the readily available kits for making frames as “containing a partially complete or disassembled billet or blank that is sold, distributed, or possessed with a compatible jig or template.” The definition adds that “a person with online instructions and common hand tools may readily complete or assemble the frame or receiver parts to function as a frame or receiver." A receiver is the equivalent of a frame for a long gun like a rifle or shotgun.

A parts kit for a Glock-style handgun. BUREAU OF ALCOHOL, TOBACCO, AND FIREARMS

Glock handguns are popular in part because of their light weight, which is due to their use of plastic for their frames. These factory plastic parts are the ones that home-brew gun makers can replace with 3D-printed parts.

What is a ghost gun?

The term “ghost gun” elicits concerns that these weapons are not detectable by TSA agents at airports. But the guns not only employ steel barrels, but ammunition is also metallic and easily detectable by metal detectors, points out the firearm industry’s trade association, the National Shooting Sports Foundation (NSSF). Additionally, modern airport scanners can easily see the plastic parts too.

3D printers can employ a variety of materials when they make parts and printing gun parts seems like an especially critical application, so you’d want to be sure to use the best material for the job. 3D printer “ink” is called filament because the plastic material feeds into the machine in the form of what looks like fishing line.

The best filament material for firearms parts, according to 3DGunBuilder.com, is Polylactic Acid (PLA), according to the site. “PLA+ is the clear winner when it comes to the 3D firearms community,” it states. The “+” indicates material that is stronger and less brittle than standard PLA, producing parts that are less prone to cracking. Additionally, PLA+ has better adhesion between printed layers, producing smoother, more consistent parts.

Nylon, polycarbonate, and PETG, which is familiar milk jug polyethylene terephthalate (PET) with glycol added for flexibility and impact resistance, are alternative materials for 3D printing firearm frames. However, “PLA+ is the clear winner with its excellent durability, heat resistance, and ease of producing quality 3D prints,” the site concludes.

Guns like this whose frames are printed at home are not required by federal law to be marked with a serial number unless they are taken to a licensed gun shop for service.

3D printing versus kits

The kits for building guns at home are not simple snap-together pieces. Kits are preferred for assembling DIY guns because consumer-grade 3D printers are very slow to make the required parts. These kit parts are required to be marked with a serial number, unlike home-printed parts. In either case, the owner must perform various machining operations on the blank 3D-printed pieces to make them functional, explains the NSSF.

In a 2022 interview with ABC TV affiliate KMBC in Kansas City, firearms expert Ben Bitler outlined the process. “This is not something that’s done easy,” he explained. “It does not take 30 minutes to build one of these. It takes hours if not days to build one of these kits,” he said.

“End users are required to perform meticulous drilling and labor with hand tools in order to make a working firearm component,” noted the NSSF. Why would they do that? “The benefit to this hobby is being able to build a personalized firearm with the particular parts the owner wants rather than purchasing a fully functioning firearm and incurring the added expense of swapping parts for a customized look and feel,” said the foundation.