What does California's 3D printer firearm law (AB 2047) require?

The act defines it as "hardware, firmware, or other integrated technological measures capable of ensuring a three-dimensional printer will not proceed to any print job unless the underlying three-dimensional printing file has been evaluated by a firearms blueprints detection algorithm and determined not to be a printing file that would produce a firearm or a machine gun conversion device" (3273.632(d)).

The act borrows the existing definition in Civil Code 3273.60(d): a "computer-aided manufacturing device capable of producing a three-dimensional object from a three-dimensional digital model through an additive manufacturing process that involves the layering of two-dimensional cross sections formed of a resin or similar material that are fused together to form a three-dimensional object." That definition is not limited to machines built or marketed for firearms.

The act sets up a chain of steps, each depending on the one before it (3273.633):

1. Check for a standard. Beginning no later than July 1, 2027, and quarterly after that, DOJ must check whether ASTM International (formerly the American Society for Testing and Materials) has published industry standards for equipping 3D printers with firearm blocking technology.
2. Decide feasibility. The next step applies only if DOJ determines that ASTM has published or adopted standards and that they show it is technologically feasible to equip printers with the technology.
3. Publish minimum standards. DOJ then has 24 months to publish written guidance or regulations describing the minimum performance standards a printer must meet "to be lawfully sold or offered for sale in California." These must be developed in consultation with stakeholders. DOJ may also set up a process for manufacturers to self-certify each printer make and model.
4. Sales rule begins. One year after DOJ publishes, the requirements on manufacturers and sellers start.

If, as of July 1, 2029, DOJ determines that ASTM has not published standards, DOJ "shall not be required to make any further determinations."

Once the rule begins, two things apply (3273.633(c)):

• Before a manufacturer sells, offers to sell, or transfers for consideration a 3D printer to any person or business in California, it must ensure the printer has firearm blocking technology that meets DOJ's minimum standards.
• It becomes unlawful "to sell, offer for sale, or transfer for consideration" a 3D printer in California that is not so equipped.

The act speaks to sales, offers, and paid transfers. It contains no rule about possessing or using a printer. The sections added by the bill also do not state a fine, a criminal penalty, or another enforcement mechanism.

• Props. The section "does not apply to printers used exclusively for the manufacturing of properties (props) in the entertainment industry" (3273.633(d)).
• Future exceptions. DOJ may adopt regulations with additional exceptions if they are consistent with the act's purpose (3273.634(b)).
• Developers of the technology. The existing civil liability for distributing digital firearm manufacturing code does not apply to a person who distributes that code "solely for the bona fide purpose of developing, refining, and testing the functionality of firearm blocking technology" (3273.633(e)).

AB 2047 itself takes effect January 1, 2027, and its first deadline falls on DOJ, not on the public. But older laws already apply to 3D printers and firearms:

• Manufacturing. No person other than a state-licensed firearms manufacturer may use a 3D printer to manufacture a firearm (Penal Code 29185(a)).
• Firearm-specific machines. It is unlawful to sell, offer to sell, or transfer a 3D printer "that has the sole or primary function of manufacturing firearms" to anyone in California other than a state-licensed manufacturer, and unlawful for anyone else to possess, purchase, or receive one (Penal Code 29185(b) and (c)). Subdivisions (d) and (e) of the section list exceptions. A violation is a misdemeanor (Penal Code 29185(f)).
• Digital files. A civil action may be brought against a person who knowingly distributes digital firearm manufacturing code to a person in California who is not a federally licensed manufacturer or other listed recipient. The Attorney General, a county counsel, or a city attorney may seek a civil penalty of up to $25,000 per violation (Civil Code 3273.61).

For how these rules fit with serial number requirements, see California ghost gun and serialization rules.