I found this (H/T to Anonymous Conservative) interesting:
the only 3D printing systems in the world capable of automatically reinforcing engineering plastics to aluminum levels of performance and beyond, right on your desktop.
Aluminum levels of performance? That probably doesn’t include all parameters and all grades of aluminum but I could imagine it being good enough for a gun barrel accurately shooting hundreds of rounds of low speed, soft lead bullets before needing to be replaced. And if the gun was made correctly replacing the barrel could be quick and easy.
That tech really is the nail in the coffin of gun control. As soon as I can print a pistol that will reliably and safely shoot several hundred round for a price point of a couple hundred per pistol or less, the game is over. All the gun control in the world become totally useless.
Of course that assumes that some majority of the population are rational thinkers. The gun control arguments have been based on emotion rather than rational logic for years, and they still keep coming.
What a frightful thought! The only solution to that is to either ban 3D printers, or require background checks for their purchase, restrict the sales of certain types of extrusion media (limiting hardness to, say, the consistency of Gummi Bears), and perhaps restrict the capacity of civilian-available machines to a print size of less than a bar of soap. Only through sensible printer control can we keep our streets safe for the children.
… and perhaps restrict the capacity of civilian-available machines to a print size of less than a bar of soap.
Wouldn’t help. I’m sure someone (probably multiple someones) can come up with a design for a 3-D printed multi-shot pistol under those constraints. The worst-case scenario is that your frame/receiver and slide (if it has one) come out in two or three parts that have to be fastened together. Not ideal, but not that difficult to engineer around.
And besides, a mini-revolver easily fits that size constraint…
True. I’ve seen 5-shot .22s that are smaller (except for width) than a derringer.
Yes, that’s the one I’m referring to: NAA 22LR. Not very comfortable if you load it with high velocity 22LR, but it works. And they offer a holder for it that’s a belt buckle. Not clear if that would be open carry or concealed. Better avoid using that option in fascist states…
https://markforged.com/materials/ has some more details. It seems a bit stronger/stiffer than 6061 alloy aluminum, which is admittedly not all the way to the limit of what aluminum can do but pretty good.
An interesting option for application that involve shock loads is kevlar (rather than carbon or glass fiber) reinforcement.
The main question I can see is whether you could make a rifled barrier with this. The issue is the wear involved, unlike what a smoothbore has to deal with. Perhaps if the round has a soft outer jacket, like the plastic rings seen on some artillery rounds (if I remember right)? Or a thin soft sabot?
And yes, since the victim disarmers are neither interested in nor capable of rational thought, this won’t make any real difference in the debate.
Rifled barrels have been done with laser-sintered metal powder printers. The barrel is built standing on end as an upright cylinder, and with sufficient precision the rifling is built layer by layer, with the rest of the barrel cross-section.
Also, there’s no reason to use a pattern that simulates cut or broached rifling. Polygonal rifling, like a Glock barrel, or more of a 5R pattern would probably be easier to make, actually. Or, take it a step further and print a gain-twist barrel, which gently imparts the twist to the projectile. This would be just as easy to print, and would probably make the rifling last longer.
I don’t know if you can blend the media in a print job, but it would be interesting to “plate” the chamber and throat with a harder, more heat-resistant material to resist erosion, and perhaps a more resilient material farther out?
heat is going to be the issue in using that material for a barrel. They’re saying 140C is the “heat deflection point” which I take to mean Tg. That’s the point where mechanical properties of the composite break down as the matrix transitions from more solid to more liquid.
That’s not to say you couldn’t have a composite barrel, there are quite a few composites that will handle extreme temperatures, they’re just big $$
I asked recently if it would be possible to make that machine spit out something like epoxy resin. Not clear if that would work.
On rifling, I was just thinking about this kind of scheme: make a core the diameter of the bore, take a couple of strands of something like piano wire wrapped around it in a gentle spiral, then make the barrel around that. Remove the core, leave the wire in place, presto… rifling.
Another possibility, probably more sensible, is to use a skinny tube as the liner (rifling cut into that) so the printed material is the outer shell and structural support, but not the part that is most directly exposed to heat and wear.