But I won’t really worry until there’s such thing as a home elemental-transmutation kit that can make critical masses of plutonium.
You know somebody would do it, just for shits and giggles.
Were it possible. Might or might not ever be.
The real concern would be that machine’s power supply.
The hand-wringing over printable guns is a bit humorous for reasons already noted, but I would point out that the 3D printing technology that exists today would be quite useful in circumventing a high-capacity magazine ban.
Would be a heck of a lot easier and cheaper with a sheet metal brake, hydraulic press, welder and a spring. I have access to all of those, a horizontal mill would make the dies really easy, that means a trip to Dad’s house. Point is, it would take me about a day to set up the tooling and then I could mass produce 30rd mags all day long. Cheap and easy
Capt
Looks good.
Well, that’s a self-solving problem, isn’t it? 
Well, the FP45 Liberator can be stamped out of metal and assembled in the old style high school metal shop, so it could be made in a basement. I would imagine that you might actually be able to print-sinter many of the parts and use a segment of pipe bought from a plumbing supply for other parts of the gun. Zip guns have a long and [dis]honorable history. And the Finns invented the molotov cocktail which was produced in a factory in the Winter War.
You have molotov cocktails, what are you worried about
“Chemputers” are vaporware. They’re not actually printing chemicals on-demand; they’re just printing beakers and such that they can then use in basically old-fashioned ways to do chemistry. Having a bunch of beakers of custom shapes and sizes would no doubt be handy, but it’s in no way revolutionary.
range
Any gun made by a 3-D printer will be, at best, a cool-looking single-shot, and will most likely be dangerous to the user. There is a reason that barrels are forged and machined, and even then occasionally suffer structural failures. I’m certainly not overcome with concern over what amounts to a gun made entirely with MIM-type components. Anything that requires pressure resistance and/or elasticity like a recoil spring certainly can’t handle the stresses.
A 3-D printed gun is probably the very last thing anybody needs to be worried about.
They have made reasonably reliable stripped lower receivers
Is there something I misunderstood about that video I just posted?
They’ve only been able to 3D print an AR-15 lower receiver. Now, legally speaking, that lower receiver is the actual “gun”, but that’s nonsense in RL terms.* It’s not a “3D printed gun” if after printing out the parts you have to go out and obtain a normal upper receiver, barrel, etc.
*though it is significant for being able to circumvent regulations.
Ah, thanks for clearing up my ignorance.
Maybe that he only made one little piece of the gun in a 3D printer? Most of the rest of the components were forged / milled out of metal (at least all the critical ones). There’s no way that today’s 3D printers could make a barrel or a bolt that wouldn’t be more of a hazard to the shooter than the shootee.
I don’t know how worried I’d be with a plastic firing pin