Not in rapid succession. We do this with mortar rounds and PVC - you can fire once an hour because they swell. Swollen barrels jam. Jammed bullets blow up barrels. Thermoplastics suck ass for any sort of kinetic task. 3D printing could use thermosets, but they also suck ass for any kinetic task. Thing of it is, barrels are easy to make. You don't need a 3d printer to make a gun - you need a piece of pipe and a nail. Which should scare you more than some goofus with a makerbot.
I think that's because, like most geeks enamored of 3D printing, you do not have a firm grasp on what is possible with small-scale manufacturing today. Even if they switched over to xenon lasers and sintered metal powder, a 3D printer would still be limited to low-force, low-work-energy products. Look at it this way - inkjet printing allows you to print out nifty photos in full color from your house. If you want to print something that lasts, however, you're going to go to a big, professional house that does 4-color offset printing, same as you would have back in 1982. Granted - the Internet has opened up those houses to the rank and file. I can now get a book of my kid's first four months off Shutterfly for like $20. But as far as the actual product made, better results are available with less effort to trained professionals with traditional tools. I first messed around with 3D printing in 1997. It's awesome for rapid prototyping. You make your thing into an STL file, hit the glue, and then cast it up using lost wax or sandcasting and you have a real part. Lost wax and sandcasting have been available to the home experimenter for over 10,000 years. But nobody messes with them because they require skill. This little gun basically makes it so that goofuses with a $2000 printer no longer have to buy a piece of pipe and follow the instructions in the Anarchist Cookbook to make a zip gun. They can just print it out. In the end, though, they're both going to run afoul of a metal detector... and the piker with the Anarchist Cookbook will be able to fire more than 4 shots out of his saturday night special.
Interesting. I'd be the first to admit rank ignorance about 3D printing, especially what it's capable of at the present time. In the future, though, I see no reason to bet against 3D printing being another in a long line of technologies that we underrate. It might end up the opposite, too. It'll be fun to watch regardless.
The reason to bet against 3D printing is it is now, has always been and shall always be a prototyping technology. As lots of geeks are into making one of a "thing" a prototyping technology is exactly what they need. however, geeks who actually have a modicum of understanding of metallurgy and manufacturing processes have been making one of a "thing" for centuries. It's cheaper, stronger, generally faster and, I say this having been on both sides, a HELL of a lot more fun. Check out Gingery Books. If I can injection-mold shit out of coke bottles using a drill press, why the fuck would I spend $96 for 3lbs of ABS?
The reason to bet against 3D printing is it is now, has always been and shall always be a prototyping technology.
I hope not. And I imagine no one would be making a big deal out of it if it didn't have the potential to be much more accessible than the techniques in the videos on that site. I don't know that it does, because I've just become interested in it -- I'm just assuming from the level of attention it's gotten compared to other similar tech. It may ultimately prove to be just another modern digital art form. That's cool too.
3d printing is to manufacturing what desktop printing was to printing. Yeah, you don't need to go to Kinko's any more. But if you want to print out 100 pages of a thesis, it's still cheaper to go visit Kinko's. The reason "everyone" is making such a big deal about it is that with 3D printing, you don't need to understand the first fucking thing about manufacturing - you just need to be able to run Sketchup. Just like you don't need to understand CMYK printing to print out a photo of your daughter. The difference being, desktop printing is marginally more expensive than workshop printing with incrementally fewer materials choices... while 3d printing is orders of magnitude more expensive than traditional manufacturing with radically fewer materials choices. Hubski has a hard-on for 3D printing because there's a willful insistence on not understanding it. Which makes sense - the only people who had to learn materials science were mechanical engineers, so only mechanical engineers really understand how hard 3D printing sucks for anything but prototyping. "Prototyping" isn't a well-understood word anyway.
The difference being, desktop printing is marginally more expensive than workshop printing with incrementally fewer materials choices... while 3d printing is orders of magnitude more expensive than traditional manufacturing with radically fewer materials choices.
And neither of those things will change? "shall always be a prototyping technology"? If that's the case, I agree with you. Again, not an expert or even a hobbyist.
"Prototyping technologies" are those with no economies of scale. If you're injection molding, you get efficiencies when you're making 10, 100, 0r 1000. If you're printing books, you get efficiencies when you're making 10, 100 or 1000. Hell, collating is an efficiency. 3D printing is always a 1-off. Every time you make a new one, it's the same as if you were making it the first time. Just like using an inkjet printer- every time you run it, it's the same as if you were running that photo the first time. WIth "manufacturing" you can use "anything." With 3D printing you can use "soft, melty things." It will never change.
If I could buy a 3D printer for $400 that burned fishing line, I'd do it. I think Candyfab is awesome. Bathsheba Grossman is doing this stuff exactly right - "let's use 3d printing to do the stuff we can't do any other way." But I've also done sandcasting. I've also done lost wax. Hell - my dad made my parents' wedding rings out of 1950s dimes using a coffee can and investment wax. And I'm here to say - the materials you can reasonably work with in 3D printing are a far cry from the materials you want in your life... and the materials you want in your life aren't as hard to work with as most people think.