California Bill AB 2047 Would Force 3D Printers to Block Firearm Prints

California Assembly Bill 2047, introduced by Assemblymember Rebecca Bauer-Kahan, would force consumer 3D printers sold in the state to include software that scans STL and other CAD inputs and blocks files linked to firearms or illegal gun parts before a print begins. Yahoo’s summary of the bill states “all 3D printers sold in California will be required to include firearm detection algorithms and software controls that identify files designed to produce guns and illegal gun parts, then block those printing requests,” and PCMag reports Bauer-Kahan framed the move as public-safety driven: “This legislation takes a proactive approach to public safety by ensuring that 3D printers sold in California include the technology to block the production of illegal firearms.”

The bill, as described in 3DPrintingIndustry, centers on software-based detection rather than hardware changes and would require algorithms to scan common 3D file formats such as STL and other CAD-based inputs. 3DPrintingIndustry says the measure directs the California Department of Justice, or another designated agency, to study existing firearm blueprint files and detection tools and to establish performance standards for what the bill calls “firearm blueprint detection algorithms” by July 1, 2027, with certification of approved systems expected to begin at the start of 2028.

Enforcement is two-track: civil remedies and criminal penalties. Civil actions could target companies that sell non-compliant printers or file false attestations, with penalties including damages, injunctions, and fines up to $25,000 per violation, according to 3DPrintingIndustry and NRA-ILA excerpts. On the criminal side, 3DPrintingIndustry reports that knowingly disabling or working around the blocking systems with intent to produce firearms, or distributing modified printers for that purpose, would be treated as a misdemeanor. Several outlets, including PCMag’s reporting of an Adafruit blog post and NRA-ILA, reference a March 1, 2029 date tied to roster compliance and criminalization, though 3DPrintingIndustry’s timeline only specifies the DOJ’s July 1, 2027 standards deadline and a 2028 certification start, leaving a timing discrepancy to be reconciled in the bill text.

The bill carves out specific exceptions, 3DPrintingIndustry reports, for printers made exclusively for licensed firearms manufacturers, law enforcement use, military use, and certain industrial settings not sold on the consumer market. Still, industry pushback is already visible: Adafruit warned the proposal risks “useless surveillance software” and, as PCMag quotes Adafruit, wrote “If your printer isn’t on the list by March 1, 2029, it can’t be sold. In addition, knowingly disabling or circumventing the blocking software is a misdemeanor,” a phrasing that highlights vendor fears of a state-maintained roster of approved makes and models.

Coverage cites law-enforcement context motivating the bill: PCMag notes Bauer-Kahan referenced a Sonoma County arrest where police recovered three 3D printers and 157 handguns, many appearing to include 3D-printed lower receivers. Other reporting, including SlashGear, stresses technical limits, observing that “you mostly can't print an entire gun” and that receivers remain the commonly regulated component requiring background checks.

If enacted as reported, AB 2047 would push manufacturers to register and certify models with the DOJ, expose non-compliant sellers to civil fines up to $25,000 per violation, and criminalize certain circumvention behavior; the legislation’s July 1, 2027 standards deadline and the reported March 1, 2029 roster date together create a narrow compliance runway for vendors, makerspaces, and anyone relying on open-source or aftermarket firmware.