Federal law requires that a person or business engaged in the sale of firearms be licensed. A finished firearm bears a unique serial number and must be registered with local authorities. Additionally, a person buying a firearm must meet certain requirements (for example, not be a convicted felon), and submit to a background check before purchase. However, it is legal to make and own a firearm as long as it is intended for personal use only and the user does not intend to sell it. An individual need not obtain a license to make a firearm, nor must the gun be registered. (18 U.S.C., Chapter 44; § 922 (d).) This includes firearms created with 3D printers, except in New Jersey and California, as discussed below.
For more information on the legality of homemade guns, specifically those made by a 3D printer, see Are Downloadable Plans for 3D Printed Guns Legal?
At the end of 2013, Congress extended the existing Undetectable Firearms Act for an additional ten years, which makes illegal any firearm that cannot be detected by a metal detector. This means that a plastic-only 3D printed firearm must also have a metal plate inserted into the printed body. However, additional proposed legislation that effectively would have banned 3D printed guns in their entirety failed to pass through Congress, and no change to the existing law was implemented.
Only a few state and local governments have attempted to or implemented 3D printed gun regulations and provisions.
In 2018, the California legislature passed a new law that requires gun owners to obtain a serial number from the state's Justice Department for any firearm the person possesses or manufactures, including homemade guns. In order to obtain a serial number, the person must show compliance with required background checks and safety classes. The person then must permanently stamp or affix the serial number on the weapon. The law also requires that a plastic firearm have a small amount of stainless steel embedded in the plastic with the serial number for the weapon engraved or permanently affixed to it.
In 2018, New Jersey enacted its law prohibiting anyone who is not registered to manufacture firearms from manufacturing 3D printed guns. The law also prohibits distributing digital plans for 3D printed firearms to anyone who is not registered to manufacture firearms. In federal court in Texas, Defense Distributed argued that the law violates the First Amendment because the digital plans for 3D printed firearms constitute a form of speech. The judge found that its court in Texas did not have personal jurisdiction over the out-of-state defendants, such as the Attorney General of New Jersey. As a result, the judge dismissed the case at the end of January 2019, without addressing the constitutional issue. The court order is available here. Defense Distributed announced on its website that it likely will file new lawsuits in multiple jurisdictions.
In 2013, New York City introduced legislation that would have required an individual making a 3D printed gun to be a licensed gunsmith, and those possessing 3D printed guns to register them after taking possession. Both New York State and Washington D.C. attempted to criminalize the possession of 3D printed firearms in their entirety. However, none of these measures were successfully enacted.
In November 2013, Philadelphia became the first U.S. city to ban making or owning 3D printed guns. Local lawmakers acknowledged they did not know of any such weapons to actually exist in the city and the move was purely preemptive.
The United Kingdom has banned all unregistered firearms created by 3D printers. Likewise, it is illegal in Japan to develop or produce a firearm made from a 3D printer. In October 2014, a Japanese man became the first person sentenced to prison (a term of two years) for downloading and printing five plastic guns.
Proponents of regulation and/or criminalization of 3D printed firearms advance several reasons why these weapons should be regulated. Here are some of the most common theories.
Because they usually do not bear serial numbers, 3D firearms are impossible to track, and a 3D printed gun used in a crime cannot be traced. Although the law requires metal to be inserted into the weapon, monitoring compliance with that requirement is virtually impossible because there is no federal oversight.
Before entering into the settlement agreement in the Defense Distributed lawsuit, the federal government had taken the position that 3D printed firearms are a danger because releasing their digital blueprints on the Internet would give anyone, anywhere in the world, the capability of creating a non-detectable firearm. Such a weapon could bypass airport security around the world and be used to harm Americans. These guns could also be used in international conflicts.
Those opposed to regulating 3D firearms are concerned that regulation will suppress 3-D printing technology in general, which could result in negative long-reaching effects on 3D innovation. They point to the positive uses of 3D printing technology, such as the creation of objects for both personal and manufacturing use; and the potential for extraordinary feats of engineering, like bio-printing human body parts for medical purposes and other innovations in fields such as electronics, transportation, and space exploration.
The controversy over 3D printed guns has brought a great deal of negative media attention to 3D printing technology. Such publicity has caused some manufacturers to restrict access to their products in some cases. For example, when a printer manufacturer learned the group Defense Distributed planned to use its leased 3D printer to develop a homemade handgun, the printer manufacturer terminated the lease and seized the printer. (The printer was ultimately returned once the group obtained a firearms license.) Opponents of regulation argue that, if manufacturers seek to protect their legal and financial interests by restricting access to individuals or groups whose 3D products invite controversy, development of the technology itself will be stymied.
The process of developing appropriate regulations and laws regarding 3D printed firearms looks to be a long one that will stretch into the next several years, if not decades. At this time, possession and manufacture of 3D firearms is not a crime or otherwise prohibited in the United States, but as legislation and regulations develop, those who build 3D firearms may find the weapons subject to registration or serial number requirements like those just enacted in California. In addition, more states may enact laws like New Jersey meant to limit the making of 3D firearms to registered gun dealers and manufacturers.