The California House of Representatives recently passed a bill considered to be the most radical regulation of 3D printing currently, aiming to deal with the rapid growth of untraceable 3D printed guns in recent years. The bill, numbered Bill 2047 and titled the California Firearm Printing Prevention Act, passed the House of Representatives with 58 votes in favor and 19 votes against, and is now submitted to the Senate for consideration.
According to the content of the bill, consumer 3D printers sold in California in the future must be pre-installed with "firearm blocking technology" and the design files submitted by the user will be checked before the printing task begins. Printers are required to run a "gun blueprint detection algorithm" on STL files, CAD files and other geometric codes. Once a file capable of producing a gun or illegal gun parts (including modified devices) is identified, printing must be blocked.
The bill requires the California Department of Justice or other relevant state agencies to develop performance standards for detection algorithms and software control processes by January 1, 2028. Subsequently, 3D printer manufacturers must submit a self-declaration of conformity for each model they plan to sell in California by July 1, 2028. The state government will publish a public list of compliant and non-compliant models before September 1, 2028. Starting from March 1, 2029, the sale of any 3D printer not included in the compliance list will be prohibited.
For manufacturers or sellers who continue to sell non-compliant printers, the bill sets a maximum civil penalty of $25,000 per violation. At the same time, any person who knowingly and with the intent to manufacture a firearm knowingly disables, uninstalls, bypasses or otherwise circumvents the blocking software, or distributes a modified printer for the purpose of manufacturing a firearm, will also be guilty of a misdemeanor.
Supporters of the bill believe that this measure starts from the source and curbs the danger before "downloadable files" become "untraceable weapons." The gun control advocacy organization "Everytown for Gun Safety" pointed out that in 20 cities in the United States, the number of 3D printed guns seized by the police has increased nearly 10 times in the past five years, and cheaper and more powerful 3D printers have been widely used in illegal "ghost gun" production activities.
However, the bill also faced strong criticism from digital rights groups and the maker community. The Electronic Frontier Foundation calls the proposal "censorware" and warns that it may force users to be locked into a software ecosystem approved by manufacturers, threaten the survival space of open source firmware such as Marlin and Klipper, and potentially push file detection to the cloud, thus raising privacy concerns. Some makers also pointed out that gun parts are often geometrically similar to ordinary mechanical parts, so it is difficult for algorithms to avoid misjudgments.
The report also mentioned that Colorado has taken another path to regulate 3D printed guns through HB26-1144. The bill was initially worried that it would criminalize the "possession of 3D firearm documents", but the final written version focused on "knowingly and through 3D printing means to produce firearms or parts that may be functional" rather than pure document possession. California's approach, by contrast, has been described as almost "going in the opposite direction" - trying to regulate by exerting control over the printers themselves before anything physical takes shape.
If the entire legislation passes the Senate and eventually becomes law, it will set an unprecedented set of technical barriers to entry for 3D printing equipment, and may also trigger a new round of controversy and legal challenges between privacy rights, open source software ecosystem and public safety goals.