3D Printed Revolver | Hacker News Reader

3D Printed Revolver

popsci.com

41 pointsbane53 comments

"In Australia’s province of New South Wales, thanks to a law passed earlier this month, merely owning the files could land a person in prison for 14 years.

Wow, that's pretty harsh. I have read about Australia's gun confiscation program but I didn't realize they banned possession of computer files. I wonder how that could even be enforced. What if you just rename the file to "bunny rabbit" or some other innocuous thing?

And what about 3-D printing parts of a gun separately? A barrel for example is basically a tube. Will they ban tubes? The grip is just a grip. Useful for finger strengthening. The cylinder is a candle holder. Etc.

Just piece it together and you accidentally, coincidentally have something that happens to shoot. As for bullets - hm, homemade bullets have been around for centuries. I would suspect it's possible to make bullets from scratch even in a place like Australia or Japan.

Bottom line: bans don't work, and 3-D printing merely makes it easier to circumvent clumsy, 1930s style laws.

> I wonder how that could even be enforced.

It couldn't. What it can do, though, is to aggravate sentences for "bad people" when arrested for other crimes. Raid a dealer's house, get laptop, "find" (cough cough) 3d-print files, threaten perp with 14 years extra, get him to confess to the original crime, job done.

This is why 1930s laws stay on the books -- they can always be useful here or there.

In a movie I saw (Existenz) there is a scene where someone pieces together a gun firing teeth from a bunch of stuff they find in their meal. All the bits individually look very gross but are not immediately recognizable as parts of a weapon.

In the words of Chris Rock: we don't need gun control, we need bullet control.

https://www.youtube.com/watch?v=Db0Y4qIZ4PA

Bullets you can make from stuff too. We need propellant control. But then everyone will switch back to knives and blunt objects. What we need is kinetic energy control.

Newer powders are hard to make, but black powder is actually relatively easy to make from what I understand. You certainly won't be shooting modern quality ammunition, but guns are still possible. The .38 special was originally a black powder cartridge if I'm not mistaken. That's why the case is so large compared to the actual quantity of modern gunpowder that you use.

    > I didn't realize they banned possession of computer
    > files

I wonder how hard you would have to think to find other examples of computer files whose possession would get you in to trouble?

Yeah, ouch. Thanks for pointing that bit out. I won't download it then =/

People love these 3D printed gun stories... but they don't realize that a drill press and a metal file are really all you need, and they make a better gun too...

I think one of the reasons is that using a drill press and a metal file require some skill whereas it takes much less skill to download a design and hit 'print'. Even so the quality of low cost 3D printer printed objects is such that you'll definitely need that file (and maybe even that drill press) so from that point of view not much has been gained.

Substituting plastic for metal in a gun is a great way to lose a couple of fingers or an eyeball too.

We used to teach middle schoolers to use such tools. It was a class called "shop" or maybe "industrial arts." Who ever thought they might be used to make a gun. Oh wait -- that was the project of one of the kids in my shop class, ca. 1979.

Yep. All knowledge is 'dual use', and metal working skills more so than most.

Yea, totally, but this all assumes you can get ammo too. That's way harder than making a gun.

Maybe a 3D printed taser would actually be more accessible?

Given the amount of energy in a typical smartphone battery, I've wondered about making some sort of replacement back, loaded with supercapacitors and a couple of contacts, so the entire phone could double as a stun-gun ...

With a little bit of creative re-wiring it might even double as a grenade.

Hah! My wife owns one of the Samsung S3s with the 'swelling battery' problem; those things are almost grenades out of the box :)

People really underestimate the potency of a cell phone battery. It always makes me laugh how the airline security check will confiscate bottles with baby milk and water but lets through a couple of hundred high energy batteries without a problem (laptops, cellphones, tablets). Now what could a creative terrorist do with a few phone batteries and some wire. Might even be enough to burn through the cockpit door of an airliner.

Two things:

1. Don't give them ideas. I have a bunch of LiPols I want to get back home with next week.

2. I've heard and repeated that fact, but come to think of it it still makes me wonder - do hand grenades really have so little energy?

The trick of a grenade is not the amount of energy that it packs, it is the duration over which it releases that energy.

Compare with a balloon. You blow it up with a little bit over atmospheric pressure over a large amount of time. But when you puncture the balloon all the energy is released over a very short amount of time.

This is also why relatively harmless firecrackers become a lot more violent when you constrain them using duct tape or some fracturable container.

Re. 2, yes, but much https://en.wikipedia.org/wiki/Explosive_material#Brisance

Thanks, didn't know that word before!

I don't know about that, but you could probably make some sort of thermite-phone, with a flammable body ignited by the energy in the battery. If done carefully, you could possibly have the thing behave like a fully functional phone until ignited. Doubt it'd bring down an airliner but it'd cause no end of panic and chaos onboard.

Being somewhat practical oriented I've half a mind to try to see what kind of a 'bang' one could get out of a cellphone or laptop battery but I have two worries: the first that it will succeed, the second that it will succeed a bit too well resulting in people no longer being allowed to bring laptops and cellphones on board of airliners and I have enough enemies as it is ;)

It's strange that nobody tried this to date (or at least, I can't find any hard evidence about people trying to blow stuff up with cell phone or laptop batteries).

A fully charged 1000mAH 3.7V battery contains ~ 13kJ of energy. One gram of TNT gives you ~4kJ. So at best - assuming you had some way of efficiently exploding a smartphone battery - you'd get a couple grams of TNT yield.

I suspect shocking, burning or smoking would be a better route to weaponising a smartphone.

Edited: for comparison, the muzzle energy for a .50BMG round is ~15Kj. Bearing in mind you get ~4kJ from a gram of TNT, this explains why being shot hurts so much :)

Laptop batteries do 200-400 Kj, that's 50 to 100 grammes of TNT.

I'm not sure how much damage one could do with 100 grammes of TNT but surely you could find more than just one laptop battery to work with.

Working grenades use anywhere from 50 grammes or more of TNT filler. The damage would very much depend on how fast you can liberate that energy and how well you could focus the blast.

At least a few of you are currently being added to the no fly list.

Also, relevant https://xkcd.com/651/

> At least a few of you are currently being added to the no fly list.

As long as they don't add me to the 'no drive list' I'm fine with that.

> Also, relevant https://xkcd.com/651/

That's pretty much word-for-word, funny!

I should have been added to that after I broke a light aircraft learning how to land them ;)

The guy who made this gun also made a pistol out of metal

https://www.youtube.com/watch?v=tvqIgnclZTg

I think there's something to be said about the liberty that this kind of thing gives to people in general.

This is a bit of a touchy subject but I think that in the case of overthrowing an oppressive government this kind of thing certainly makes defending yourself a lot easier.

Would be interesting to see these given to young woman in many parts of the world, who can't otherwise go out unaccompanied without fearing attack.

The argument "They'd just be used against the women!" seems hollow as most are just strong armed with muscle power alone by the goons justifying it with "they were asking for it", etc.

What's the difference between giving these and giving existing revolvers?

I meant via bypassing gun laws and or import restrictions.

If you think this thing is going to be any use against even the lowliest army rifle then good luck to you.

... just like a bunch of hicks with Kentucky rifles couldn't be of any use against the greatest military power the world had ever known to that point (1770s), with its vast navy, cannon, artillery, and mercenaries.

It's no longer the 1770's. If you wish to engage in revolution with a bunch of plastic guns and low power bullets be my guest but it's your funeral.

A Glock is also largely made of plastic, but the barrel is made out of steel. Presumably this is because they would like to be able to fire it many times and because this greatly reduces the risk of injury to the user of the gun.

It's hard to cut useful rifling into anything but metal or ceramic.

A revolution mainly just takes strength of numbers; it's different from a war. The Berlin Wall fell without a shot, for the most part. And there's an awful lot of killing going on in urban areas of Israel right now with just blades. Likewise, 9/11 was accomplished with just tiny blades.

> Likewise, 9/11 was accomplished with just tiny blades

tiny blades and the idea that you shouldn't fight back.

Could be useful for getting through metal detectors for an assassination. All you need to do is get the bullet through and you can hide that in a cap or a shoe.

I've seen that movie.

http://www.imdb.com/title/tt0107206/

I don't see how this is going to be of use for anything else than crime. It's too dangerous for home defense, but just about OK for shooting someone point-blank.

Do you really think that, even if widely available, this would be used more often for crime than for harmless purposes like simply experimenting with 3D printers?

You can experiment with 3D printers just as well by printing toys for kids or plastic roses, simple machinery and other gizmos. Once you decide to print an unlicensed, unregistered gun and get ammo you'd better be prepared to use it for something because in a large number of places you've just crossed into illegal territory which would seem to be a lot of trouble to go to just to 'experiment with 3D printers'.

I don't think that you'll get much mileage out of that line for your defense when you're caught with a stash of illegal weapons.

No, your honor, those 25 guns are misprints, really...

I'm not much of a gun enthusiast. I don't own any. But I certainly see the appeal of 3D printing a gun just to get it to work, because it's cool. The same goes for other things I think are cool, like jet engines, stirling engines, airplanes and multirotors, trebuchets, 3D models of fractals, complex gear systems, etc. I'd be interested in printing all of these things just as a hobby, and a 3D printed gun is no different. There's no reason why a gun is unique, such that I or the average 3D printer hobbyist would only be interested in printing one to commit a crime.

Small arms are used to gain large arms. That's how it always works.

If you manage to get close enough. Rifles have range, this gun does not. It will definitely kill you at close range but you're going to have to get there and you should hope your opponents are very few in number.

I could be wrong because what do I know about guns, but when I see these I-made-a-gun stories, I'm really irritated because 1. it seems like the action of someone who began with "What is the easiest thing that I could do that would get the most media attention?" 2. when an important technology is young, it is so irresponsible to stoke fears for selfish reasons in the populace or abet politicians and pundits doing the same.

A lot of 3D printing is like JavaScript: See, I can do 'X' with JavaScript, where 'X' in JavaScript is not better or even a proper application of the technology, but it is new to the maker and it is new to their audience.

Making a gun from plastic was doable for many years (various epoxys, simple casts) so no news there, in principle.

But making a gun (or a whole bunch of them!) with a push of a button and without skills is definitely new and that's the reason why it is newsworthy.

So even if the tech is wrong, the product crap and the workmanship shoddy there is something new here: a lethal weapon that can pass through a metal detector can be manufactured by anybody without skills. They still need ammo, they are manufacturing guns (which in many places can get you into a very large amount of trouble), they're showing that 3D printing is an enabling technology.

As noted below there are better ways of making guns, but they require a little bit more in terms of skills (but less in terms of investment, and the guns will be much better).

Guns are easily obtained on the black market in any country in the world. I'd be much more concerned about 3-D printed nuclear bombs or 3-D printed surface-to-air missiles or, in the not-too-distant future, nanotech 3-D printed tailored viruses :(

That's a really crappy gun. It's not even a revolver; a revolver has one barrel with multiple rounds in a cylinder. This is a pepperbox gun, an idea from the 1830s that didn't work out. The barrel length is so short you can't hit anything other than at point-blank range.

If you're going to design a 3D printable gun, design something better than what can be machined. Maybe bring back the Gyrojet or something like that.

Note that they're using .22LR ammunition, which has low recoil. They are also likely using subsonic ammo, which is even lower powered. Anything higher powered is likely going to break apart plastic.

I'd love to see one of these with a metal 3d printer. It would be impractical for most people to produce, but would be a cool proof-of-concept.

Note that a .22LR almost killed U.S. President Reagan and seriously wounded James Brady and two others.

With Fallout 4 being pretty popular in memes at the moment, and the fact that I've been playing a hell of a lot of it, I got a bit of a FO4 vibe from this.

Next stop, adding a scope and replacing the receiver for more accuracy and damage!

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