4 ms·

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

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. Edit: I'm not saying it makes sense, but this is the angle the congress folks are taking, sheesh.

15155 6mo ago
> 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?
- Kirby64 6mo ago
  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.
- captaincrisp 6mo ago
  And importantly the barrel. Plastic cannot contain the pressure required to fire a bullet.
- trollbridge 6mo ago
  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.
  - 15155 6mo ago
    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.
    - rolph 6mo ago
      [Primers are a legitimately difficult thing to manufacture] thats a problem that may not endure. if a firearm is reengineered to use an electrode to detonate charge rather than a chemical primer, there is no need for murcury fulminate, just a piezo electric spark generator, and a few square cm of cerebral cortex.
      - jandrewrogers 6mo ago
        Electronic primers are a thing that already exists commercially. In the early 2000s, Remington sold electronically primed hunting rifles next to their non-electronic equivalent (see: "EtronX"). It is a mature technology. The main issue is cost and simplicity, since it often requires adding electronics to weapons that normally would not require them. The military uses electronically primed cartridges for things like chain guns and autocannons, since those require electronics to fire regardless of how it is primed.
        rolph 6mo ago
        yes ive seen them they are called exotic by most people around me. yes the very nature of a chain cannon, makes electronic priming,the easier way to go. so far we can still go to the store with 20$ and come back with a 200pk of 209s, someday that might be not so easy, and electronic is the better/only way.
        Teever 6mo ago
        What advantage do they have over chemical primers?
- michaelt 6mo ago
  In the movies, you hide the bullets in a pen or something, and it bypasses the metal detector along with the keys, phones and watches.
  - ancientorange 6mo ago
    rabbits' foot, iIrc.
- esseph 6mo ago
  > What are bullets and shell casings made out of again? Usually non-ferrous metals like brass, lead, and copper unless you live closer to Russia, then you may end up with steel-case. That's besides the point though, the barrel of the gun will be steel.
  - 15155 6mo ago
    Ferrous metals aren't required for any modern security-screening metal detectors: these materials are still highly electrically conductive, and therefore easily-detectable eddy currents are still inducible.
    - esseph 6mo ago
      Oh, that's right! I remember reading somewhere about this a few years back. Might have even been here on HN. For some reason I hear "metal detector" and my brain goes right to magnetism.
horsawlarway 6mo ago
> 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=plastic+pipe 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.
kube-system 6mo ago
There was a panic about plastic guns back in the 80s too when the Glock came out, and Congress passed the Undetectable Firearms Act. But it was just as misinformed as it is today -- practically speaking, only metal is suitable for the high pressure components of a gun. A common 9mm cartridge produces upwards of 35,000 psi.
- saltyoldman 6mo ago
  Aren't there metals that are undetectable/less detectable, like titanium or even stainless steel?
  - jandrewrogers 6mo ago
    No, it doesn’t work like that in the modern world. The nature of the materials are pretty obvious to a remotely competent sensor.
    - RugnirViking 6mo ago
      using what physical process? How exactly do they detect any metal? A genuine question.
      - kube-system 6mo ago
        You can detect nonferrous metals by inducing eddy currents in them, then they become magnetic.
redsocksfan45 6mo ago
[dead]
mvrekic 6mo ago
I don't care how good you are, you cannot 3D print a barrel that will withstand the pressure forces generated by a centerfire round.
- Aurornis 6mo ago
  Kind of interesting how many of these comments are confidently denying what the 3D printed gun nuts already pulled off 13 years ago. I would never in a million years want to be around one being fired, but there have been big internet communities pulling this off going back a long time https://arstechnica.com/tech-policy/2013/11/feds-get-in-on-3d-printed-firearm-game-but-one-gun-exploded-instantly/ https://arstechnica.com/tech-policy/2013/11/feds-get-in-on-3...
  - imtringued 6mo ago
    You just linked an article that shows that entirely 3D printed guns don't work.
jcgrillo 6mo ago
If you're dead set on making a gun that will pass through a metal detector you don't need a 3D printer to do it.

15155 6mo ago

> 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?

Kirby64 6mo ago
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.
captaincrisp 6mo ago
And importantly the barrel. Plastic cannot contain the pressure required to fire a bullet.
trollbridge 6mo ago
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.
- 15155 6mo ago
  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.
  - rolph 6mo ago
    [Primers are a legitimately difficult thing to manufacture] thats a problem that may not endure. if a firearm is reengineered to use an electrode to detonate charge rather than a chemical primer, there is no need for murcury fulminate, just a piezo electric spark generator, and a few square cm of cerebral cortex.
    - jandrewrogers 6mo ago
      Electronic primers are a thing that already exists commercially. In the early 2000s, Remington sold electronically primed hunting rifles next to their non-electronic equivalent (see: "EtronX"). It is a mature technology. The main issue is cost and simplicity, since it often requires adding electronics to weapons that normally would not require them. The military uses electronically primed cartridges for things like chain guns and autocannons, since those require electronics to fire regardless of how it is primed.
      - rolph 6mo ago
        yes ive seen them they are called exotic by most people around me. yes the very nature of a chain cannon, makes electronic priming,the easier way to go. so far we can still go to the store with 20$ and come back with a 200pk of 209s, someday that might be not so easy, and electronic is the better/only way.
      - Teever 6mo ago
        What advantage do they have over chemical primers?
michaelt 6mo ago
In the movies, you hide the bullets in a pen or something, and it bypasses the metal detector along with the keys, phones and watches.
- ancientorange 6mo ago
  rabbits' foot, iIrc.
esseph 6mo ago
> What are bullets and shell casings made out of again? Usually non-ferrous metals like brass, lead, and copper unless you live closer to Russia, then you may end up with steel-case. That's besides the point though, the barrel of the gun will be steel.
- 15155 6mo ago
  Ferrous metals aren't required for any modern security-screening metal detectors: these materials are still highly electrically conductive, and therefore easily-detectable eddy currents are still inducible.
  - esseph 6mo ago
    Oh, that's right! I remember reading somewhere about this a few years back. Might have even been here on HN. For some reason I hear "metal detector" and my brain goes right to magnetism.

horsawlarway 6mo ago

> 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=plastic+pipe 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.

kube-system 6mo ago

There was a panic about plastic guns back in the 80s too when the Glock came out, and Congress passed the Undetectable Firearms Act. But it was just as misinformed as it is today -- practically speaking, only metal is suitable for the high pressure components of a gun. A common 9mm cartridge produces upwards of 35,000 psi.

saltyoldman 6mo ago
Aren't there metals that are undetectable/less detectable, like titanium or even stainless steel?
- jandrewrogers 6mo ago
  No, it doesn’t work like that in the modern world. The nature of the materials are pretty obvious to a remotely competent sensor.
  - RugnirViking 6mo ago
    using what physical process? How exactly do they detect any metal? A genuine question.
    - kube-system 6mo ago
      You can detect nonferrous metals by inducing eddy currents in them, then they become magnetic.

redsocksfan45 6mo ago

[dead]

mvrekic 6mo ago

I don't care how good you are, you cannot 3D print a barrel that will withstand the pressure forces generated by a centerfire round.

Aurornis 6mo ago
Kind of interesting how many of these comments are confidently denying what the 3D printed gun nuts already pulled off 13 years ago. I would never in a million years want to be around one being fired, but there have been big internet communities pulling this off going back a long time https://arstechnica.com/tech-policy/2013/11/feds-get-in-on-3d-printed-firearm-game-but-one-gun-exploded-instantly/ https://arstechnica.com/tech-policy/2013/11/feds-get-in-on-3...
- imtringued 6mo ago
  You just linked an article that shows that entirely 3D printed guns don't work.

jcgrillo 6mo ago

If you're dead set on making a gun that will pass through a metal detector you don't need a 3D printer to do it.