Personally, I see this as an assault on 3d printing more than any real attempt to regulate guns.

I own several 3d printers. If I wanted to make something resembling a firearm I'd go to home depot WAY before I bothered 3d printing parts. You basically just need a metal tube, and well... a pipe from home depot does that much better than trying to 3d print something much less reliable.

So given we don't do this regulation for any of the much more reliable ways to create unregistered firearms... what's special about 3d printers?

So my assumption is immediately that some relatively large lobbying group feels threatened by 3d printing, and is using this as a driver to try to control access and limit business impact.

Either way, this is bad legislation.

I'm not on top of the current SOTA in 3d-printed guns, but the way it typically was done in the past is that you don't actually 3d-print all of what you or I would call a complete gun.

The barrel will be metal. In designs made for the US market, it will almost certainly be an actual manufactured gun barrel, since gun parts other than the receiver are not closely tracked in the US. In designs for Western Europe, the metal parts will be either milled or things you can buy at the hardware store[1].

The barrel and chamber being made of something tougher than you can get from an FDM machine is basically a requirement for making a gun that doesn't explode in your face when you shoot.

1: Here's an image of all of the parts going into a gun designed to be made in the EU. Per the wikipedia article, the barrel rifling can be added with electrochemical machining https://en.wikipedia.org/wiki/FGC-9#/media/File:FGC-9_Compon...

whats special is speed and consistency.

when you manufacture a personal firearm, it is supposed to be yours, for your use. the 3d printer aspect, makes it possible for a group to print large quantities of receivers, under the radar, to be combined with "accesory parts" close to "drop-in" assembly style.

At issue here is that anyone can build a 3D printer. There's one in my basement a hobbyist built entirely from easily-sourced parts, and the controller is entirely open source. It never phones home and isn't really connected directly to the Internet at all.

Careful. Or they will try to regulate ghost printers.

> any real attempt to regulate guns

Any real attempt would need to be at the national level, not that I would advocate for it, but it's simply a pipe dream to create a "gun free zone" in a country with 100s of millions of firearms. There are plenty of gun enthusiasts in California, they just don't flaunt it or talk about it.

Not that I support any of these obviously stupid bills but:

> what's special about 3d printers?

They can make guns made out of plastic and metal detectors are kind of the primary way we try to find guns on people.

You are probably right about the lobbying group, I agree.

> They can make guns made out of plastic

So can many, many other things. Hell - something like this will do SO MUCH BETTER than anything I can print:

https://www.mcmaster.com/products/pipe/carbon-fiber-1~/?s=pl...

It's weird because 3d printed plastic is WAY down the list of things I'd prefer to trust handling the explosion from ammunition.

Frankly - even the hobbyist CNC I have is a MUCH better method of creating a plastic gun. FDM printing is not something I'd want to trust in this case, neither is SLA printing in most materials (some of the very high end ones like nylon in a formlabs printer... maybe?).

But my point stands - guns aren't that hard to make, and we aren't trying this legislation with any of the other myriad manufacturing methods. Hell - compare to a potato cannon... (also a plastic gun, btw...)

So what's different about 3d printers?

My hunch is this has fuck-all to do with guns, and a lot to do with something else, because 3d printers ARE different in that they let me manufacturer all sorts of other, much more complex, goods much more easily and cheaply at home.

> metal detectors are kind of the primary way we try to find guns on people

What are bullets and shell casings made out of again?

More importantly, what is the barrel made out of? Yes, I know there’s some fully printed guns… but my understanding is that those are basically 1-time use and even then it’s questionable how reliable that single use actually is…

If you want something resembling an actual gun (more than one shot, won’t blow up in your hand, some reasonable chance of accuracy, etc), then you’re going to be using multiple metal components (including the bullets of course) all of which would show up on a metal detector.

And I'd argue that shell casings are probably harder to manufacture than a fully working firearm. The equipment needed to manufacture working ammunition end-to-end is pretty serious.

All of these manufacturing equipment and processes existed more than a century ago.

If you have a capable VMC, you can make the die and other equipment necessary to stamp shell casings from commonly-available parts and machinery.

From there, with a modern Dillon or Hornady reloading press, you can crank out thousands of rounds per day without issue.

Primers are a legitimately difficult thing to manufacture, but (good-enough) bullets, casings, etc. are completely doable.

And importantly the barrel. Plastic cannot contain the pressure required to fire a bullet.

The 3d printer gun legislation has been rearing its head in a bunch of states this year, and generally with very similar patterns. I suspect some of the pro-gun-control groups have been pushing it to lawmakers given most legislation is basically copy-pastes from lobbying groups at both the state and federal level. Colorado, Washington, New York, and now California have all floated legislation attempting to make device-level restrictions around the issue. I only followed Washington's in depth, and they ended up removing all the requirements on manufactures, but did criminalize possession of files which I suspect won't hold up to a first amendment challenge.

I really think all of this is the result of Mangione. Regulating 3D printers has been talked about for years with no action. Then a year after the CEO of a large well known company is killed with a 3D printed gun the states are suddenly pushing highly invasive 3D printing laws. It's no coincidence NY was the first to push for such a law, the state where said CEO was killed.

LM has a whole series of videos that touches on this (as well as some related topics): https://www.youtube.com/@LoyalMoses/videos

Louis Rossman also touched on the topic: https://www.youtube.com/watch?v=kS-9ISzMhBM

I've seen more by others but can't recall them all. Without going too far down a conspiracy theory rabbit hole, the momentum for this seems to be coming from a variety of sources:

    * New York being New York and trying to make thinking about guns a thought crime
    * There's European company (forget the name) that makes specialized software that can do this.  They're lobbying so they can inject themselves for some tasty rent seeking.
    * A variety of companies that see right-to-repair (and thus home 3D printers, CNC-milling, etc.) a threat to their bottom lines.
    * General ignorance by our law makers

Edit: And I personally think instead of doing stupid bullshit like this, we should be giving EVERY kid who wants one a free 3D Printer so they can learn to tinker, be creative, and build things. That's how we create that spark that leads to the next generation of makers. Without that our country will continue to be the country that can no longer build things.

Lets imagine a similar situation but instead of with an additive manufacturing process they try to regulate a subtractive manufacturing process: a traditional CNC machine. There is no way to prevent the CNC system from machining gun parts as along as the machining is done in discrete steps with the same work piece. The software can't know what sitting on the CNC table.

In additive manufacturing it is more difficult but not impossible to print a bunch of pieces that look nothing like a gun part but and in the end be assembled into a gun.

In both the above cases there would need to be sophisticated surveillance software to even come close to detecting "gun-ness."

While I don't have a horse in the gun control race, I do have one in the open-source, running a local OS, running what software I want, and controlling what that software does races.

Some of these bills are written in such a way that they would apply to CNC manufacturing, such that they could even make building your own machine from scratch illegal. They are terribly oppressive and short-sighted.

WA state's legislation includes subtractive methods, CA's omits it so that they don't have to deal with the wrath of Haas.

Omitting subtractive methods makes it rather toothless, since there have been places you can go to push a button to start a mill making you a receiver (which is the part that is considered "the gun" to address ship-of-theseus questions aboug guns), then you can add the other parts yourself.

> The primary goal is clear and simple: to require 3D printer manufacturers to use a state-certified algorithm that checks digital design files for firearm components and blocks print jobs that would produce prohibited parts.

"state-certified algorithm" has a really nice tyrannic ring to it. I am sure once this has passed the rich people can finally sleep at night knowing they are safe from roving gangs of armed Mangiones.

A 3D printer, at least of the Prusa variety, is really just a bunch of stepper motors and a dumb motor driver executing a series of effectively "rotate by X steps" commands, which is what the gcode file is. It doesn't know what it's printing. It doesn't even know that it's a printer.

If they wanted a gate on designs it would have to happen in slicing software, not the actual printer.

Indeed. I grew up in a a machine shop than ran both manual and CNC machines and spent my summers in from of mills and lathes running jobs. I now do industrial automation and machine repair. With that being said, yeah, no way will this work. Ever.

And software? My Bridgeport and Logan were built before computers were available to the home consumer. Good luck stopping someone like me.

So, I cannot 3d print a squirt gun or a nerf style gun either? This print looks "scary" you cannot print it.

waste of time and resources. you aren't going to win a fight against 3d printers. might as well outlaw the printers completely.

A. What if some part looks like some other non-gun part? B. What if they can further break down the pieces to avoid detection?

Why don't these bills go after ammo or gunpowder access? Seems as long as you have access to a cylinder, and ammunition, you can make a gun.

blackpowder is just barely chemistry, more like engineering.

carbon, sulphur, and potassium nitrate, in a particular ratio.

potassium nitrate is watched, and reported in large quantities, or particular form, but can be manufactured by most people that can follow a recipe.

regulating the propellant cant stop it from being made.

also someone really didnt think it through by regulating "receivers"

they regulated what is most often the easiest part to manufacture. the core parts [barrel, bolt, chamber] are difficult to build, require tech to build from stock, and are sold off the shelf, while receiver needs 4473 as if it was a fully functional firearm, and that is the part that can be built, from a 2x4 or a billet of material, depending how long you want it to last.

Black powder guns, at least ones of antique design (but modern production), are federally ~unregulated already anyways. A 6 year old in North Dakota could order one mailed right now to his house, no background checks, right off the internet -- legally.

There is also the "felon carry" as its called late 19th century black powder percussion pistols, you can also order off the internet, regardless of criminal history and with no scrutiny of the chain of custody.

because gun control isn't about guns, it's about control

I don't know the situation with the actual charge, but if you can make a gun, you can certainly make ammunition.

you need tight tolerances for modern ammo, a shotgun, or muzzle loader is more forgiveing. reloading materials are not federally regulated as firearms, you just dont want to have more than 2lbs at a time, or that could bring trouble.

you want to be able to KNOW and SEE the difference between a blackpowder, and a smokeless powder, and what not to put it in.

one thing that would add a lot of friction is if the primers are regulated.

thats the funny thing, felons cant possess firearms or ammo, however you can possess reloading materials, and be fine there until you start actually reloading, then you are in possession of ammo.

I guess you are right, both are pretty easy to make.

People would probably use smuggled primers if arms were outlawed. The rest of the chemistry is easy enough to work with and the primers are small enough they'd likely flow along with fentanyl with the cartels anyway.

> For regular people to own a gun that you can actually use in California, (not LEOs or certain other people), you either needed to have inherited them or bought them from the cartels.

or, you can just break these stupid, unenforceable laws and buy out of state or just "uncastrate" it yourself.

no idea why so many people get their panties in a twist everytime California passes an unenforceable law. they're unenforceable.

They’ll be selectively enforced

I've always felt if you really want to impact election fraud, tax the hell out of votes. Like $1,000/vote. For those who believe in democracy, a handful of votes over a lifetime is all you need, and ideally the right candidate wins anyway.

Could probably create exceptions for local elections, so you can still participate in your community.

Tricky part would be general elections, but restricting such a tax to federal races is probably an 80% solution.

> I've always felt if you really want to impact election fraud, tax the hell out of votes. Like $1,000/vote.

You don’t even have to go that far. $10 and a trip to the DMV is apparently an insurmountable barrier.

> Could probably create exceptions for bullets used at the gun range, so you can become proficient and safe.

Amusing to imagine the red diesel of sport shooting - better hope the tax authority doesn't find any combustion-proof dye on the self-defense shell casings!

I could ask LLM to find me "legal" parts that are 1:1 with gun parts or even better find metal parts in craftcloud3d.com or sendcutsend.com. With big enough database it could find right items on Amazon. It's impossible to legislate.

> California's proposed legislation to put the burden of blocking 3D-printed firearms onto printer manufacturers

I can only assume California has solved all its major problems if policing 3D printers is at the top of the agenda. It's like when someone complains their neighbor can afford two yachts and they can only afford one, you know they are doing pretty well if that's their major concern.

I'm so glad I left California 6 years ago. They are going to regulate and tax their startups and innovators away to other states. This is supremely stupid.

This is the inevitable result of having a single-party government which is no longer accountable to regular citizens.

We are sorry, but your print resembles random princess from Disney too much (actually, we won't tell you which). Just following the law you know..

I don't understand the problem solving mindset that thinks banning guns would solve the problem of a person intent on causing harm.

In the U.K., where I feel guns are only showpieces (do even cops have them?), stabbing is a known problem.

In India, where ammo is way more expensive than machetes and knives, people are literally murdered with them.

The only argument I can understand, when it comes to banning guns, is that it reduces the blast radius that an evil person can have.

So what's next, lock down the air, radio, roads, internet, water, food supply chains because these are all attack vectors?

If that's the proposal, what's my plan when coyotes and mountain lions attack my child and I on our regular walks on rural property?

guns democratize mass murder. With a gun, I can kill a bunch of people before police can stop me. A knife? At best I can kill one or two in a public place before people run away and eventually a different group is going to stop me pretty quickly.

Killers are going to kill. Guns don't democratize it, just makes it easier. Maybe at best YOU could kill one or two:

https://www.cnn.com/2024/11/16/china/china-stabbing-yixing-c... (8 stabbed to death) https://en.wikipedia.org/wiki/Chenpeng_Village_Primary_Schoo... (1 killed, 24 injured)

So they should stop you from 3d-printing knives too.

- can you build bombs to blow up an apartment complex full of 1000s of people?

- can you poison the water supply of an apartment complex full of 1000s of people?

- can you drop a harmful substance using a $50 drone onto an open area where of 1000s of people have congregated?

We also restrict the components of those pretty heavily, though. Try buying too much fertilizer without a farm and see who shows up.

This isn't a judgement on your general point, but I think bombs and bioweapons and etc are very bad examples for you here.

Source: https://www.eff.org/deeplinks/2026/04/dangers-californias-le... (https://news.ycombinator.com/item?id=47759420)

It's ridiculous that this is even being discussed. The people proposing the bill must have zero understanding of how a 3D printer works.

It makes as much sense as requiring saw manufacturers to implement protections that restrict what can be cut out with a saw.

Or pen manufacturers being required to enforce copyright.

Any form of this bill will 100% fail to attain its stated objective, while having horrendous not-quite-unintended consequences.

And in the end, what's to stop someone from assembling an unlicensed 3D printer to make unlicensed prints? That's how the industry literally began.

(Not to mention: what do they think would happen to the hundreds of millions of existing "dumb" 3D printers? They won't disappear because there's a law).

Sigh.

> Any form of this bill will 100% fail to attain its stated objective, while having horrendous not-quite-unintended consequences.

California gun laws in a nutshell.

> what do they think would happen to the hundreds of millions of existing "dumb" 3D printers?

Hey, my printer might be going up in value.

I'm surprised the EFF didn't address the issue that traditional printer manufacturers already comply with law enforcement, specifically that a fingerprint of yellow tracking dots [1] are printed and printers will often refuse to or fail to copy images of money.

My point is there's already precedent for printers cooperating with authorities so one can see this as simply an extension to 3D printer manufacturers.

I suspect it's a losing battle for the EFF and 3D printer manufacturers to resist some kind of fingerprinting or even the prohibition of things that are guns.

I'm not saying that's right or wrong. That's just what I expect to happen. And if you want to argue against it, you should address the printer tracking dot issue or argue how this is different.

[1]: https://en.wikipedia.org/wiki/Printer_tracking_dots

> how this is different

From purely a technical standpoint: the printer indiscriminately adds tracking dots to all documents, the proposed 3D printer regulation requires the printer to phone home and make some dispositive call on what it's allowed to do.

Open source is core to 3d printing. I have never heard of an open source traditional printer. That is the difference. This is an attempt to lock down open source.

I believe EFF did address the yellow dots but got nowhere. Yellow dot problem is decades old.

I just laugh whenever I hear “ghost gun”.

> On January 13, 2014 a certain State Senator (no reason to name names) held a press conference where he held a modern rifle in his hands and stated, “This is a ghost gun. This right here has the ability with a .30-caliber clip to disperse with 30 bullets within half a second. Thirty magazine clip in half a second.”

Anyone that knows even a little bit about guns knows that this is utter nonsense, and it was appropriately memed into oblivion.

Most anti-gun activists and legislators seem to have no more knowledge than this - which is to say, none.

Hence "assault weapons" which are not a particular type of gun but a list of scary characteristics associated with military weapons—bayonet lugs, folding stocks, and the like—used by legislators to FUD their way into being seen as "doing something" about guns.

In the United States we even have a word for an assault weapon on four legs—pitbulls. Most breed-specific legislation, where it exists, targets pitbulls which are not a single breed nor group of related breeds, but basically any large muscular dog with a short snout and blocky head. The American Pit Bull Terrier is one such breed but far from the only one targeted by BSL.

I think it was Toyotomi Hideyoshi who said something like, the law is not obligated to logic, but it still must be followed.

> Anyone that knows even a little bit about guns knows that this is utter nonsense

Most people in California who vote on these matters have not held a BB gun, let alone a semi automatic.

They have 0 idea that you just cannot buy actual guns from a grocery store in California anymore!

They think you can just buy a gun at Walmart like you can buy a can of Coke. I was able to pull up clips made in 2023 and 2025 that were literally claiming that. Hasn't been true since atleast 2009, likely even earlier.

A few years ago a local Walmart was clearing our their air gun and rifle selection after there had been a shooting on the east coast that was all over the news. Since ammo have become really expensive, I bought out the whole shelf of air rifles so I could continue to target practice with a focus on my breathing.

People called the cops on me. Multiple people verbally abused me as a gun nut and recorded me buying them on their phones. I had air guns - *children* *toys*. They thought it was the real deal!

The local sherrif's department received nearly a 100 calls that hour when we spoke. When I asked them why they even bothered to turn up because they know no Walmart in a 300 mile radius have ever sold a rifle in the last 20 years as was described to them over the phone, they just shrugged and said "politics".

AFAIK If I try to scan a dollar bill, both the hardware and the software won’t let me be.

How is this different?

A dollar bill is exactly the same (roughly) always. Banning models of gun parts (or anything 3D printed, for that matter) is like trying to ban the patterns of dust in the wind. There are millions of permutations and ways to slice the problem.

Photoshop does that voluntarily; it's not required to by law. GIMP doesn't do it.

This is akin to trying to require all image editors to detect currency and refuse to process images of it. Making open source image processing software would probably have be illegal because end users could trivially modify it to illegally process currency, or having general-purpose computers that can run software the government hasn't approved would need to be banned.

US currency has machine-detectable identifying markings incorporated in the design. "Ghost gun" parts do not.

One practical difference is that you can make dollar bill detection relatively robust. Sure, you could cut it into 4 pieces and scan them separately, but you'd still get stuck when it comes time to print them. There are only finitely many dollar bill shapes. But there are infinitely many plausible gun components, and infinitely more ways to divide them into sub-assemblies.

> but you'd still get stuck when it comes time to print them.

It also seems a lot harder to DIY an inkjet or laser printer. The parts needed to DIY a 3d printer are a lot simpler.

It would be interesting to test what the minimum detectable piece of US currency is. (I wouldn't want to do it on a network-connected system, though.)

There is a pattern of yellow dots on the currency. I do not know at what size they tile across the paper, but the piece of currency would have to be smaller than that, most likely.

Far easier to dump the firmware and NOOP out that algo.

You cannot defend yourself from a hungry coyote or surprised mountain lion with a dollar bill but you can certainly protect yourself or your child from one with a gun