3D printed firearms

In 2012, the U.S.-based group Defense Distributed disclosed plans to "[design] a working plastic gun that could be downloaded and reproduced by anybody with a 3D printer." Defense Distributed has also designed a 3D printable AR-15 type rifle lower receiver (capable of lasting more than 650 rounds) and a 30 round M16 magazine. Soon after Defense Distributed succeeded in designing the first working blueprint to produce a plastic gun with a 3D printer in May 2013, the United States Department of State demanded that they remove the instructions from their website.

In 2013 a Texas company, Solid Concepts, demonstrated a 3D printed version of an M1911 pistol made of metal, using an industrial 3D printer.

Effect on gun control
After Defense Distributed released their plans, questions were raised regarding the effects that 3D printing and widespread consumer-level CNC machining may have on gun control effectiveness.

The U.S. Department of Homeland Security and the Joint Regional Intelligence Center released a memo stating that "significant advances in three-dimensional (3D) printing capabilities, availability of free digital 3D printer files for firearms components, and difficulty regulating file sharing may present public safety risks from unqualified gun seekers who obtain or manufacture 3D printed guns," and that "proposed legislation to ban 3D printing of weapons may deter, but cannot completely prevent their production. Even if the practice is prohibited by new legislation, online distribution of these digital files will be as difficult to control as any other illegally traded music, movie or software files."

Internationally, where gun controls are generally tighter than in the United States, some commentators have said the impact may be more strongly felt, as alternative firearms are not as easily obtainable. European officials have noted that producing a 3D printed gun would be illegal under their gun control laws, and that criminals have access to other sources of weapons, but noted that as the technology improved the risks of an effect would increase. Downloads of the plans from the UK, Germany, Spain, and Brazil were heavy.

Attempting to restrict the distribution over the Internet of gun plans has been likened to the futility of preventing the widespread distribution of DeCSS which enabled DVD ripping. After the US government had Defense Distributed take down the plans, they were still widely available via The Pirate Bay and other file sharing sites. Some US legislators have proposed regulations on 3D printers, to prevent them being used for printing guns. 3D printing advocates have suggested that such regulations would be futile, could cripple the 3D printing industry, and could infringe on free speech rights.

United States
In the United States, it is legal for individuals to manufacture firearms for personal use without a license, however this does not extend to some firearms such as Title II weapons (machine guns, silencers etc. ) or Assault Weapons in jurisdictions which still ban them.

Under the Undetectable Firearms Act any firearm which cannot be detected by a metal detector is illegal to manufacture, so legal designs for firearms such as the Liberator require a metal plate to be inserted into the printed body. The act has a sunset provision of December 9, 2013. Senator Chuck Schumer has proposed renewing the law, and expanding the type of guns that would be prohibited. Proposed renewals and expansions of the current Undetectable Firearms Act include provisions to criminalize individual production of firearm receivers and magazines that do no include arbitrary amounts of metal, measures outside the scope of the original UFA and not extended to cover commercial manufacture. These "modernization" proposals have been criticized as disingenuous attempts to suppress adoption of and experimentation with 3D printers in home gunsmithing.

On December 3, 2013, the United States House of Representatives passed the bill To extend the Undetectable Firearms Act of 1988 for 10 years (H.R. 3626; 113th Congress). The bill would extend the Undetectable Firearms Act, but not change any of the law's provisions. Some Democrats, including Senator Schumer still want to expand the law to include more specific provisions directed at 3D printed guns.

Other locations
Manufacture of firearms by unlicensed individuals is illegal throughout most of Europe and Asia.