I dunno about steel. For one, plastic doesn't set off metal detectors, so making a non-metallic projectile to go with your plastic gun would make them perhaps still not the most stable weapon ever, but certainly one that's invisible to metal detectors.

The ability to conceal a such a weapon in a casing that can look like almost anything your printer can produce could pose a security challenge that's pretty difficult to detect under current methods.

I'd print out a gun that looks like this:

http://i.ebayimg.com/t/McDonalds-Night-Museum-SQUIRREL-Loose-/ 15/!BpQTZtg!mk~%24(KGrHqMH-DEEuUwY0E21BLqlB9surw~~_35.JPG

It is important to understand that you only need to print the regulated part that classifies something as a firearm. 90% of a gun can be bought right over the counter no questions asked. The guy who printed the AR-15 lower receiver claims it stands up perfectly fine. And even it wore out after a couple hundred rounds... just print another one.

Yeah, I've seen the AR lower thing before. It's pretty cool as a work-around to gun laws. But that's not what these Wiki Weapon dudes are talking about: They want to model a pair of original guns, one of which would be made completely out of plastic, as a safeguard against "tyranny", as if America isn't already swimming in firearms.

The materials right now are going to limit the reliability and safety of something like a gun but that's not going to be true forever or even for very long.

I'm not a gun fan but this is certainly a coming challenge for the practicalities of gun ownership control in the same way that the internet/mobile communications make existing copyright legislation and attempts to control information flow look increasingly unworkable.

I guess the "safeguard against tyranny" argument can be made for this even alongside a stance that doesn't support a general right to bear arms. For practical tyranny-fighting purposes a population that can print a working weapon in a few hours is not much different to one that has them already.

Barring some stupendous advances in material science, I don't see 3D printed plastic guns as being anywhere close to as effective as current(or even hundred year-old) metal weapons.

It'd be like if the Pirate Bay existed, but you could only download in grainy black and white with shitty sound.