California passes bill requiring gun-blocking software in 3D printers

California’s Assembly advanced AB 2047, a bill that would require consumer 3D printers sold in the state to scan design files for firearm or prohibited-part blueprints and block flagged prints.

The proposal also sets deadlines for state standards, manufacturer compliance filings, and a public list of approved printer models, with a future sales ban on noncompliant devices.

Supporters say it could help curb untraceable ghost guns, while critics warn about privacy, false positives, and limits on open-source firmware like Marlin and Klipper.

If enacted, California would join a small group of states testing firearm-blocking 3D printer rules, following similar efforts such as Colorado’s HB26-1144.