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 Samus_aran115 wrote:
Impossible. There's no way a plastic firing pin could be manufactured with a 3D printer to survive the tolerances that would be required of it. Forget about the barrel, which would be burned up and bubbling before the bullet left it. I also doubt a plastic slide would work. If it did, Glock would be using them.

This is silly. I understand that it would set a precedent though.

I'm more worried about people making lightning links and other automatic crap in their garages with equipment they can buy from harbor freight

Plastic slide would definitely not work. The weight of the slide is the "equal and opposite reaction" part of the equation - with a blowback or unlocked action, the weight of the slide is greater than the bullet, thus the bullet goes out the barrel.


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 Samus_aran115 wrote:
Case in point, the Bullet Button

Most of the federal laws make total sense. State laws get kind of silly sometimes, but nothing is as bad as california. I don't know why anyone who has even a slight interest in guns would want to live there. But, it's still better than most of the rest of the world.

You not actually read any federal laws or regulations have you?

 Frazzled wrote:

Plastic slide would definitely not work. The weight of the slide is the "equal and opposite reaction" part of the equation - with a blowback or unlocked action, the weight of the slide is greater than the bullet, thus the bullet goes out the barrel.

I might work, but it would be awful to shoot.

 dogma wrote:

 Frazzled wrote:

Plastic slide would definitely not work. The weight of the slide is the "equal and opposite reaction" part of the equation - with a blowback or unlocked action, the weight of the slide is greater than the bullet, thus the bullet goes out the barrel.

I might work, but it would be awful to shoot.

I don't think it would work unless you changed the entire breech design into something not been done before. Good luck with that.
You could make a zip gun, revolver, or lever action but meh. Again, its plastic. I don't think it could contain the pressures sufficiently to not turn into a nice hand grenade in your face. I could be wrong.

Just wanted to chime in that the license in Maryland is sort of a joke. You watch a 15 minute video, which you can do ONLINE, and then print out a paper card and sign it. There is, literally, not a single actual instance of oversight. Now, when buying a handgun you have to put the card number on the paperwork, but again, it's not like the police are matching your gun license to your driver's license.

It would be stupidly easy to fake, and I think is done more for 'extra prosecution' purposes than anything else.

Frazzled wrote:

You not actually read any federal laws or regulations have you?

Well. Gun rights are usually dependent on the state. I can only think of a handful of things that are national, like the ATF's policy, and the national gun registry that the police use to keep tabs on murder weapons and other things. As much as I dislike the ATF (more of a second-hand sort of hatred), they do serve a function, and things are probably safer as a result. I'm sure that could be debated, since the ATF has its hand in all sorts of cookie jars.

Yeah, Maryland laws are ridiculous. It's hilariously easy to buy a gun, but you're out of luck if you actually want to legally carry it around. If we could just take baltimore, and give it to Pennsylvania. Then you'd be left with a pretty reasonable, safe state!

While I don't like the idea of a printable gun, it is a good proof of concept that you can make almost anything with those 3D printers. I'd like to see where this tech goes. this may honestly be something worth investing in. (the 3D printer tech, not the printable gun)

 Samus_aran115 wrote:

Frazzled wrote:

You not actually read any federal laws or regulations have you?

Well. Gun rights are usually dependent on the state. I can only think of a handful of things that are national, like the ATF's policy, and the national gun registry that the police use to keep tabs on murder weapons and other things. As much as I dislike the ATF (more of a second-hand sort of hatred), they do serve a function, and things are probably safer as a result. I'm sure that could be debated, since the ATF has its hand in all sorts of cookie jars.

Yeah, Maryland laws are ridiculous. It's hilariously easy to buy a gun, but you're out of luck if you actually want to legally carry it around. If we could just take baltimore, and give it to Pennsylvania. Then you'd be left with a pretty reasonable, safe state!

No I meant just reading the actual laws and regulations.


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And I still want a printable workable Mustang.

Samus_aran115 wrote:Yeah, Maryland laws are ridiculous. It's hilariously easy to buy a gun, but you're out of luck if you actually want to legally carry it around.

Not that I really feel the need to carry my .45 around, but Maryland's carry laws were just struck down by a federal judge. Now naturally, Maryland is appealing the ruling but I think the fed actually has the right of it. The 2nd Amendment doesn't say "Right to bear arms when you know someone wants to hurt you"...

Frazzled wrote:And I still want a printable workable Mustang.

As long as it's a Shelby Cobra, I'm in.

 streamdragon wrote:
Not that I really feel the need to carry my .45 around, but Maryland's carry laws were just struck down by a federal judge. Now naturally, Maryland is appealing the ruling but I think the fed actually has the right of it. The 2nd Amendment doesn't say "Right to bear arms when you know someone wants to hurt you"...

You won't need it until you need it.

DC's a major pain in the ass as well. The number of times I've been headed downtown only to realize I'm about one exit away from committing a felony just because I'm carrying is pretty mind-blowing.

 Seaward wrote:

 streamdragon wrote:
Not that I really feel the need to carry my .45 around, but Maryland's carry laws were just struck down by a federal judge. Now naturally, Maryland is appealing the ruling but I think the fed actually has the right of it. The 2nd Amendment doesn't say "Right to bear arms when you know someone wants to hurt you"...

You won't need it until you need it.

DC's a major pain in the ass as well. The number of times I've been headed downtown only to realize I'm about one exit away from committing a felony just because I'm carrying is pretty mind-blowing.

I completely agree re: carry, but I live in a very rural area, and work in DC. I'm not all that concerned at home, and like you said it would be a major issue in DC. Even if DC legalized, I work in federal buildings where carry would STILL be illegal. If I was going out hiking or camping (not on a state park) I'd consider it, but then I think I'd be carrying my shotgun over the .45. Realistically, I don't have much need to carry. There's always the chance some random will come at me, but where I am I feel safe enough.

 Frazzled wrote:

I don't think it would work unless you changed the entire breech design into something not been done before. Good luck with that.
You could make a zip gun, revolver, or lever action but meh. Again, its plastic. I don't think it could contain the pressures sufficiently to not turn into a nice hand grenade in your face. I could be wrong.

You can definitely manufacture plastics that match steel for tensile strength, but doing so is more expensive than just using steel in applications that are not mass dependent. Indeed, having a higher mass gun is preferable to a lower mass gun if you're firing the same rounds. Well within reason.

 Ouze wrote:

 Surtur wrote:
Wouldn't the first bullet fired kinda destroy the gun? I mean it's only a resin right? How strong is it?

Depending on what you need it for, one shot would be adequate, such as in a court setting. I don't think you could get a bullet through a metal detector though, can you?

Nope, or the rest of the gun that would be metal for that matter such as the firing pin... 3D plastic wouldn't work for a "stealth gun" application. You'd need a special built ceramic weapon with special cased ammo using special rounds

 dogma wrote:

 Frazzled wrote:

I don't think it would work unless you changed the entire breech design into something not been done before. Good luck with that.
You could make a zip gun, revolver, or lever action but meh. Again, its plastic. I don't think it could contain the pressures sufficiently to not turn into a nice hand grenade in your face. I could be wrong.

You can definitely manufacture plastics that match steel for tensile strength, but doing so is more expensive than just using steel in applications that are not mass dependent. Indeed, having a higher mass gun is preferable to a lower mass gun if you're firing the same rounds. Well within reason.

you can match strengths but the costs are prohibitive. The size difference due to weight is substantial unless you put in lead weights or something. Sure its theoretically possible, but its also pragmatically stupid.

Also, who's actually making the design specs? translation who's the idiot about to get sued out of his mind for a bad design when the first accident occurs?
Also, you have to have the printer correct? Aren't they kind of expensive?

Now a 1964 Mustang, thats choice, and so worth it.

 Frazzled wrote:

you can match strengths but the costs are prohibitive. The size difference due to weight is substantial unless you put in lead weights or something. Sure its theoretically possible, but its also pragmatically stupid.

We agree completely, you've just said what I've said up-thread.

 Frazzled wrote:

Also, you have to have the printer correct? Aren't they kind of expensive?

You need a printer for each material, all of which are expensive.

 Frazzled wrote:

Now a 1964 Mustang, thats choice, and so worth it.

No, no; this:

An SS eh? Mmm...choice. I can hear the roar in my ears just by looking at it. I suddenly feel the need to hunt something down, eat it raw, and waive its hide over my head while shouting 'the weatherman is dead!"

Would it be possible to make a sword with a metal printer?
What are the laws on those sort of weapons?

Metal printing - wouldn't that have the same strength as MIM? Er, I'm not trusting my life to that crap.

What's MIM, and why wouldn't a sword made with metal printing work just as well as a gun?
Just asking.

 CthuluIsSpy wrote:
What's MIM, and why wouldn't a sword made with metal printing work just as well as a gun?
Just asking.

Molded in Metal. Its basically metal powder mixed with glue and put into forms. The strength of it is not good. I wouldn't want a sword made from it.

I thought it was Metal Injection Molding, but I've been wrong before.

Either way, it's gotten a fairly bad rap in the firearms industry. It cuts down on costs, but when it's not done right - and it's often not - it leads to breakages, quality control issues, etc. Especially noticeable in 1911s.

So MIM is bad in general then. Ok, that's good to know.
Wait, so if Metal Printing is so bad at making weapons, then why all the fuss? Are they worried some idiot might blow his own hand off from trying to make a home made pistol?

 Seaward wrote:
I thought it was Metal Injection Molding, but I've been wrong before.

Either way, it's gotten a fairly bad rap in the firearms industry. It cuts down on costs, but when it's not done right - and it's often not - it leads to breakages, quality control issues, etc. Especially noticeable in 1911s.

You may be right. We're thinking the same thing and I didn't bother to look up the actual words. I just know it as MiM.

 CthuluIsSpy wrote:
What's MIM, and why wouldn't a sword made with metal printing work just as well as a gun?
Just asking.

Because if you want a sword to work you need proper steel and heat treating to give it the right internal crystal structure so that it isn't too brittle or too soft. It's not enough to just get the basic shape right. And even then it would be a pretty pointless idea, you probably can't get a sharp enough edge on it right out of the printer, and if you're going to be sharpening it anyway just sharpen a lawnmower blade or whatever and wrap some cloth around it for a handle.

 CthuluIsSpy wrote:
Wait, so if Metal Printing is so bad at making weapons, then why all the fuss? Are they worried some idiot might blow his own hand off from trying to make a home made pistol?

Exactly. The concern is that someone without the ability to determine whether a design is safe or not downloads some plans, prints a gun, and it explodes on them. Or, worse, they make something that works for a while (before the cracks propagate enough to explode it) and sell it (or just let their friend borrow it) and it explodes and hurts someone who didn't know they'd been given a bomb. Whether it's legal or not making your own guns is a stupid idea, and something best left to the professionals.

The finest (and most expensive) 3D Printers can manage 25microns ( 0.025 millimetres ).

That's not a particularly sharp blade, being 5-10,000 times larger than a decent edge.

You can definitely manufacture plastics that match steel for tensile strength, but doing so is more expensive than just using steel in applications that are not mass dependent.

Not to mention that tensile strength is just one of a combination of things gun materials need. Tensile strength means nothing in the face of your locking surfaces shearing away and 30,000+ PSI going where ever it decides it wants to go, for example.

I don't think it could contain the pressures sufficiently to not turn into a nice hand grenade in your face. I could be wrong.

I think you COULD do a "mostly" plastic slide if there was a delay mechanism like the 1911/glock/etc....but you'd still have a breech face and locking surface made of steel with a plastic body molded around it. I don't think I would want to do much rapid fire with plastic encasing the rapidly heating barrel either, frames get to be a half inch away and not in direct contact with the barrel, slides don't.