“I want people to walk away understanding that this is a technology bill that will cost taxpayers millions of dollars every year trying to create technology experts have said is not possible. It is also based on software that scans your data.”
— David Tobin
Executive Director, Community Manufacturing Initiative
For months, Californians have heard that Assembly Bill 2047 (Bauer-Kahan, D-Orinda) will stop criminals from 3D-printing firearms. At first glance, that sounds simple enough.
Require 3D printers to recognize firearm parts and refuse to print them.
But experts who actually build and use this technology say that’s just not true. After months of legislative hearings, testimony, and conversations with experts throughout the additive manufacturing community, one thing has become increasingly clear:
AB 2047 isn’t just a firearm bill. It’s a technology bill.
And according to many of the people who understand that technology best, California is attempting to mandate capabilities that simply don’t exist.
At Gun Owners of California, we’ve studied this bill and talked to the experts. While our mission is defending the Second Amendment, this bill raises a broader question: Can government responsibly regulate technology it doesn’t fully understand?
What AB 2047 Would Do
AB 2047 would force 3D printer makers to add “firearm blocking technology” to detect and stop printing of gun parts before their products could be sold in California. This effectively creates a new “3D Printer Roster,” requiring companies to certify their products before Californians can buy them.
Supporters argue the bill is intended to reduce the unlawful manufacture of unserialized firearms.
Critics believe it does something very different.
But engineers say the technology AB 2047 demands simply doesn’t exist. That distinction is fundamental to this debate.
A Printer Doesn’t Know What It’s Printing
One of the biggest misconceptions surrounding AB 2047 is the belief that a 3D printer somehow understands what object it is creating.
It doesn’t.
Printers follow G-code: a set of basic instructions telling the machine how to move and extrude material. By the time printing starts, the device isn’t looking at a digital gun or a machine part—it’s just following commands. By the time those instructions reach the printer, it is no longer looking at a digital model of a firearm, a robotics component, a camera mount, or a machine part.
It is simply executing movement commands.
Experts agree: AB 2047 asks printers to recognize firearm components with technology that doesn’t exist—and to somehow guess intent from geometry.
The question of intent in geometry is a significantly difficult problem.
A grooved cylinder could be a gun part—or a camera mount, robotics component, or dozens of other things. There’s no database of “firearm blueprints” or reliable way for software to guess the purpose of every design. That’s why the industry is alarmed.
The People Who Know This Technology Best Are Raising the Alarm
The most surprising critics of AB 2047 aren’t just gun owners—they’re engineers, software developers, printer manufacturers, educators, and tech advocates. Across the country, hundreds of professionals are warning lawmakers about serious technical flaws in the bill. One of those voices is David Tobin, Executive Director of the Community Manufacturing Initiative and creator of the popular 3D Printing Nerd platform. Tobin has helped organize a nationwide effort to educate lawmakers on the realities of additive manufacturing and why many experts believe the bill cannot accomplish what it promises.
Another is Marleen Vogelaar, owner of Thangs, one of the world’s largest online platforms for sharing 3D printable designs. Vogelaar has also spoken publicly against AB 2047, drawing on years of experience in the 3D printing industry.
One particularly interesting aspect of this debate involves Physna, a company that publicly claims to have developed technology capable of meeting the objectives envisioned by AB 2047. Yet while Physna says it can be done, hundreds of engineers, manufacturers, software developers, and members of the broader additive manufacturing community continue to argue that those capabilities have not been demonstrated reliably in real-world settings. At the very least, lawmakers should be asking why one company stands in such stark contrast to virtually an entire industry.
When hundreds of engineers, educators, software developers, manufacturers, and innovators all begin telling lawmakers the technology won’t work, most legislators would stop and ask, “What are we missing?” Unfortunately, Assemblymember Rebecca Bauer-Kahan appears to have taken the opposite approach—surrounding herself with applause from California’s professional gun-control lobby while dismissing the people who actually understand the technology she’s attempting to regulate.
More Than Just Firearms
One of the greatest misconceptions surrounding AB 2047 is the belief that it only affects firearm enthusiasts.
Nothing could be further from the truth.
Every day, 3D printers are used in California’s schools, libraries, startups, research labs, and manufacturing businesses. Students learn, entrepreneurs prototype, and educators inspire with them.AB 2047 threatens this entire ecosystem with impossible mandates, higher costs, and legal risk—hurting those who use 3D printing frequently and for legitimate purposes.
Let’s set the firearm debate aside for a moment.
We could spend pages explaining why criminals are far more likely to obtain firearms through theft, trafficking, or the black market than by purchasing a desktop 3D printer and teaching themselves additive manufacturing. Most Californians already understand that.
The bigger issue is that AB 2047 doesn’t stop with criminals. It reaches into classrooms, engineering labs, small businesses, public libraries, and manufacturing shops by attempting to regulate a general-purpose technology used for millions of lawful purposes every year.
It’s Not as Simple as “Push Print, Get Gun”
Another misconception surrounding this debate is that someone simply downloads a file, presses “Print,” and a functioning firearm emerges from a desktop printer.
That simply isn’t reality.
Even where it is lawful to manufacture a firearm, a consumer-grade 3D printer can only produce certain components. Completing a functional firearm typically requires numerous additional parts, specialized hardware, assembly, technical knowledge, and precision. It is far more involved than the public is typically led to believe.
AB 2047 oversimplifies both the technology and the problem it seeks to solve.
California Already Has Layer Upon Layer of Firearm Restrictions
California lawmakers keep adding new layers of restrictions—background checks, serialization, bans on unfinished parts, and more—making it nearly impossible for ordinary Californians to lawfully build a firearm for personal use, a right protected by the Second Amendment.
Now, with AB 2047, lawmakers are taking yet another step.
Instead of targeting criminal conduct, the bill attempts to regulate the technology itself.
That distinction matters.
A 3D printer is a general-purpose manufacturing tool capable of producing millions of lawful objects every day. Like computers, encryption software, artificial intelligence, and the internet itself, it is a technology that can be used for both beneficial and unlawful purposes.
The challenge for lawmakers has always been targeting criminal behavior without unnecessarily burdening lawful innovation or infringing on constitutional rights.
AB 2047 and every other California gun law get that balance wrong.
Good Intentions Don’t Guarantee Good Policy
Supporters of AB 2047 mistakenly believe they are advancing public safety.
Good intentions do not always equal good public policy.
Experts say the bill demands software do the impossible—plus, it raises digital privacy fears and big constitutional questions about free speech and government control over general-purpose technology. Before lawmakers ask courts to answer those constitutional questions, they should first answer a much simpler one:
Can the technology required by this bill actually do what the legislation assumes it can do?
Many of the engineers, educators, manufacturers, and software developers who work with this technology every day believe the answer is no.
California has long prided itself on being a global leader in innovation.
Innovation starts by listening to the people who build technology—not by mandating the impossible.
Take Action
AB 2047 is still moving in Sacramento, and your voice matters. This bill affects not just gun owners, but educators, engineers, entrepreneurs, and anyone who believes in real innovation. Tell lawmakers to vote NO on AB 2047.
You can send a letter directly to your legislators through the Gun Owners of California Action Center:
To learn more about the technical concerns raised by members of the additive manufacturing community, including David Tobin and the Community Manufacturing Initiative, visit: https://the3dprintingnerd.com/ab2047
Gun Owners of California and Gun Owners of America will continue fighting California’s anti-gun agenda in the courts and the Legislature. With major cases like Viramontes before the U.S. Supreme Court, the future of the Second Amendment in California is very much in play. If you support this fight, please consider standing with GOC and helping us press forward. Donate HERE. Donate to GOA HERE.