The Imura Revolver 3D Printed Gun

[curious aardvark]

there's no real technical challenge. It's a simple mechanism and as long as you're sensible enough to use a metal barrel - no major risk either (it'll probably still break, but shouldn't kill you).

There are soooo many things that could do with a decent design, that really would be a challenge that making inaccurate and dangerous to the user hand guns is somewhat pointless.

I can see where it might be useful for criminals in the states where you can buy ammunition at your local corner shop (maybe not all states) and to make a gun where you can't trace the rifling marks on the barrel would be useful - again mainly to criminals.

But why are the japanese getting involved ?

[WarFairy]

Hello everyone. I'm the designer of the firearm seen here. Keep in mind that this firearm has not been tested yet as it is one of the most complex prints FOSSCAD has attempted to date.

--Why is it every design uses a .38 caliber shell? It would seem other random sizes would be used?

This actually uses .22 Long Rifle. It is the most common cartridge on the planet, and only requires a single diameter of pipe to be used as the chamber and barrel sleeve. The caliber was chosen for its low power, low price per round, and simplicity in design.

--There's no other point to a 3d printed pistol than up close killing of people.

The point of 3D printing different firearms is to see what is possible more than anything. We have proven that single shot firearms are at least partially feasible in nearly 100% printed form. We have made AR-15 lowers that function for an acceptable length of time to take to a range for some target shooting. The next step was to make a semi automatic pistol. Unfortunately, with the pressures involved, there is no way to make a repeating pistol able to extract spent casings from the chamber of a fully printed barrel. The effect is somewhere between plastic flow and vacuum lock between the expanded casing and the plastic chamber wall. The solution was to use a steel chamber sleeve, but without a steel extractor, the issue still remained as to how to cycle the firearm. With Imura's design (Which was based off the Webley-Fossbery), we found the solution. That was the point to this. We wanted to solve an engineering problem that included both machine design and material properties in the core issue. I believe we have done so, but testing will tell. I'll save the ethics question for the end of this post.

--I can see where it might be useful for criminals in the states where you can buy ammunition at your local corner shop (maybe not all states) and to make a gun where you can't trace the rifling marks on the barrel would be useful - again mainly to criminals.

Its really not. The amount of effort that goes into getting a printer calibrated to the level useful for firearms parts is not insignificant or quick. Getting printed parts to an acceptable surface finish isn't trivial, and finally, there are far, far more effective weapons available for cheaper than the cost of even the most basic 3D printer. Quite simply, a 3D printed firearm would be the most circuitous and difficult path to obtaining a firearm in the US, whether acquiring a firearm legally or illegally.

--fully 3D printed plastic guns will never be practical unless ammunition is specially made for them, and that's just not going to happen.

We're workin on it. Initial tests have been discouraging, but we'll see what happens.

--Hopefully the person that designed and printed it is the first to experience it backfiring and exploding terribly in his hand, and not some kid that downloaded the design

I truly hope that doesn't happen. I've done as much as I can to make this firearm as safe as a 3D printed pistol in .22 long rifle can be. There is a significant amount of material between the user and all common failure points on a revolver of this sort, and there have been several updates to the design with safety in mind. I have made sure that the guy that is printing and testing this is using every possible precaution, including testing the first several cylinders worth of ammunition from behind cover with a remote trigger. I have no intention of letting anyone be harmed by one of my designs, and if it does not work, I'll continue to modify the design or abandon the project.

Now, as promised, the ethics of all this. Its been said here and countless other places that these things have the single purpose of killing, and that's simply not true. None of us that design these firearms want to see anyone harmed with them. We do this to push the limit of the materials and machines we have access to so that we know afterwards what works and what doesn't. We're not monsters, we're hobbyists. Personally, I hope that no 3D printed firearm is ever used in a crime, or truly anywhere but a safe environment at a range with proper and full precautions taken. They're design exercises undertaken by people like me to create something new using concepts from all over the spectrum.

I hope this post at least helps understand where we're coming from and why we do what we do. If you have any questions, concerns, or even just want to call me names for a while, feel free to contact me at www.fosscad.org/fc/chat . We welcome all, and will answer any questions you have as well as we can. I hope to talk to some of you more extensively.