California’s new bill requires DOJ-approved 3D printers that report on themselves targeting general-purpose machines. Assembly Member Bauer-Kahan introduced AB-2047, the “California Firearm Printing Prevention Act,” on February 17th. The bill would ban the sale or transfer of any 3D printer in California unless it appears on a state-maintained roster of approved makes and models… certified by the Department of Justice as equipped with “firearm blocking technology.” Manufacturers would need to submit attestations for every make and model. The DOJ would publish a list. 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. We’ve been tracking this pattern. Washington State’s HB 2321 requires printers to include “blocking features” that can’t be defeated by users with “significant technical skill” (good luck with that on open-source firmware). New York’s budget bill S.9005 buries similar requirements in Part C, sweeping in CNC mills and anything capable of “subtractive manufacturing.” California’s version adds a certification bureaucracy on top: state-approved algorithms, state-approved software control processes, state-approved printer models, quarterly list updates, and civil penalties up to $25,000 per violation. As Michael Weinberg wrote after the New York and Washington proposals dropped… accurately identifying gun parts from geometry alone is incredibly hard, desktop printers lack the processing power to run this kind of analysis, and the open-source firmware that runs most machines makes any blocking requirement trivially easy to bypass. The Firearms Policy Coalition flagged AB-2047 on X, and the reactions tell you everything. Jon Lareau called it “stupidity on steroids,” pointing out that a simple spring-shaped part has no way of revealing its intended use. The Foundry put it plainly: “Regulating general-purpose machines is another. AB-2047 would require 3D printers to run state-approved surveillance software and criminalize modifying your own hardware.” As we’ve said before on this blog, when we covered Washington and New York, it doesn’t matter if you’re pro or anti-gun. The state should prosecute people who make illegal thing, not add useless surveillance software on every tool in every classroom, library, and garage in the state. And as you can see, these bills spread – that’s how an small group can push legislation into the entire country. First, Washington proposed theirs, then New York, now California. Once those three states pass a law, that’s 20~25% of the country by GDP/population and thus every manufacturer is forced to comply with a bad decision in order to stay in business. If you’re a maker, educator, or manufacturer anywhere in the US, even outside these states, this is a problem-problem now.
Net York trying to get subtractive manufacturing CNC mills to obey this is going to be a trick.
The controller just runs Gcode for positioning and speeds. They'd need to preprocess the gcode through an AI database to check if the path builds a gun part shape then allow machining or block it.
Inevitably somebody will just replace the controller with a home grown system.
And a CNC mill can still run manual cuts a single passes that may not appear to look like a part, when done separately
This is old clueless men trying to make laws about technology they don't understand.
