Recent years have seen rapid developments in manufacturing technologies like 3D printers and computer numeric controlled (CNC) mills. These tools are legal, multi-use, increasingly available, and hold tremendous beneficial potential. They’ve also brought renewed attention to homemade (or “DIY”) firearms, fueling speculation about a new “ghost gun” epidemic.

I’ve spent the last couple years researching this topic, reviewing hundreds of documents and interviewing dozens of stakeholders in weapons interdiction, firearm law, close protection, facility security, homeland security, forensic science, gunsmithing, industrial design, and the “maker” community.

There is plenty of speculation about homemade guns. In this column, we’ll take an in-depth look at a couple common assumptions. In future columns, we’ll address some of the concrete technology, policing, and legal issues behind DIY firearms.

Assumption: Homemade Small Arms Are a “New” Phenomenon

Far from it. With the precision engineering of modern firearms, it’s easy to forget they’re a thousand-year-old technology. Modern factory production is incredibly efficient: nowadays it’s harder to make the iPhone in your pocket than the service weapon on your belt.

And in a world where sophisticated counterfeiters are illegally manufacturing smart phones, we can bet some criminals will make guns.

However, despite recent consternation, it’s always been possible to make firearms independently. Firearms were invented centuries before the industrial revolution. Today, legitimate artisanal gunsmiths continue the centuries-old craft of medieval guilds, making incredibly fine firearms for discerning collectors. In addition to licensed manufacturers and gunsmiths, many Americans (and some citizens elsewhere) construct or modify their own firearms.

In the U.S., most of this is legal. Many “DIY” gun makers are mechanically inclined sportspeople who enjoy the craft. Others are hobby engineers experimenting with new tools and materials. Some journalists, “cipher punks,” and civil libertarians have built guns or disseminated digital firearm files to encourage discussion about technology, censorship, and gun policy. In parts of the developing world, whole industries of unlicensed gun makers thrive.

“Ghost guns” are not new either. The primary concern about “ghost guns” is that they may not have traceable markings or generate chain-of-custody records. As a result, they can’t be tracked with manufacturing records, registries, or databases.

However, a great number of “normal” guns are already difficult to trace to offenders. Millions of older firearms are un-serialized. Some U.S. manufacturers serialized as early as the 1830s, but it was not universal until 1968. Even with serial numbers, compliance with tracking registries is lackluster in many countries, and dismal in the U.S.

Gun politics can be fraught with distrust. Some governments in the developing world are repressive or corrupt, and citizens may be afraid to register weapons with untrustworthy authorities. Even where government and police are very honest, some citizens fear registration based on past seizures of registered firearms. It’s difficult for registries to capture the highest-risk guns because serious violators don’t register them. Instead, illegal traffickers attempt to disconnect black market guns from their legal records, making registries and tracing systems less effective.

As a result, unregistered guns outnumber registered guns by 550-750% globally. In the U.S., a national registry is prohibited. Even so, most gun crimes are not committed by a legal, traceable, and background-checked buyer. Some surveys indicate 10% or fewer of U.S. crime guns are legally purchased by the offender. Offenders frequently steal weapons, and up to 40% of America’s crime guns may be stolen outright. Trafficked guns are also more likely to have their serial numbers defaced. (Though forensic techniques have made this more difficult).

When traffickers steal, divert, deface, part-out components, and smuggle firearms from legal supplies, they’re introducing degrees of separation between a gun’s legal records and its illegal users. Once separated from legal chains-of-custody, factory-made firearms can be nearly as “off-radar” as homemade “ghost” guns.

It has always been possible for individuals to make firearms, and for offenders to procure them without an accurate paper trail. In that sense, homemade firearms and “ghost guns” are not new at all.

Assumption: It’s All About 3D Printed Guns

Not really. There’s tremendous variety in DIY gun making.

Production may involve anything from hand tools to high-precision digital equipment. High-tech makers use digital fabrication tools like 3D printers and CNC mills. In the mid-range, a knowledgeable maker will get good results with electric lathes, drill presses, and other machining tools. On the low-tech extreme, skillful makers still produce firearms with hand tools.

DIY firearms can take many forms. “Converted” and “re-activated” firearms are prop guns, decommissioned display pieces, and other inert items altered to fire live rounds. These are practically non-existent in American crime, but a significant source of illegal weapons in some countries. “80%,” “frame,” or “receiver” builds are more common in the United States. These are made by completing partially finished over-the-counter receivers (which do not legally constitute a “firearm”), and assembling with other retail components.

“Crypto” guns don’t look like guns. There are firearms embedded within canes, flashlights, smart phones, and other nondescript items. These are typically single or multi-shot Derringer style. At the crudest level, single-shot “zip guns,” slam-fire shotguns, or pen guns require almost no skill, and are made with components from any hardware store.

An interesting sub-culture of “expedient” gunsmithing manuals has emerged since the 1970s. Its proponents argue that firearms are a human right, and citizens around the world should be able to make guns as a check against government abuse. Most of these manuals are inoffensive and do not advocate violence, but provide schematics and tutorials to facilitate gun making in any location irrespective of legalities. Many are simplified designs for World War II-era submachine guns: low-cost models intended for friendly resistance fighters to make in secret workshops.

Expedient designs circulate as digitized and paper manuals, tutorials, and how-to videos. Homemade SMGs and machine pistols based on these designs have appeared among street gangsters, extremists, and organized crime in places as varied as Australia, England, Brazil, Canada, Russia, the West Bank, Egypt, Mexico, Indonesia, and elsewhere. “Expedient” guns are inferior to industry products, but can be made clandestinely, and may involve features like full-auto fire, extended magazines, or custom suppressors.

Conclusion

You’ll notice we’ve covered a lot but still haven’t talked about 3D printed firearms! In reality, 3D printed guns are still a sideshow. The overwhelming majority of (legal and illegal) DIY activity involves conventional workshop methods, and the criminal impact of 3D printed guns remains overstated. That said, we’ve seen a trickle of criminal cases around the world, and new technologies soon promise to take digital firearms into truly uncharted territory.

In future articles we’ll cover concrete issues for DIY firearms and policing, including:

• What is the current state of 3D printed firearms?
• What are the implications for weapons screening?
• Where are homemade firearms most likely to popularize among offenders?
• Will cartels, extremists, and organized crime make guns?
• What legal, technical, policing, and civil liberties issues do homemade firearms introduce?
• How can LEOs and security professionals stay on top of this issue, while respecting citizen rights and the freedom to innovate?