The thing I don't get is how a plastic gun suddenly becomes a problem if it's 3D printed.<p>You can construct (a very crude) gun barrel for .22LR out of 3/4" plastic bar using nothing more than a 1/4" drill bit. You need a mechanism to fire the round, but since you just need to crush the primer, it doesn't have to be anything fancy. Of course you have no rifling and a poor seal so the bullet tumbles and isn't effective more than 10-20 ft away, but it's deadly up close.<p>Since plastics became commonly available over 50 years ago, I don't understand why everyone is suddenly concerned about plastic guns from 3D printing. What is a criminal more likely to do, buy a 3D printing machine for several hundred dollars, learn how to use the software correctly and print a gun OR just buy some plastic and make one himself for $10 and a few hours of his time?
Title doesn't (really) reflect that this was part of a test, and not that someone was found to have smuggled a 3D printed weapon in.<p>Also, the article does not mention whether or not ammunition was smuggled as well; I'd imagine that'd be harder to hide from a metal detector than plastic -- and the gun isn't much good without bullets.
Pre-9/11, my dad forgot a large serrated bread knife in his backpack when entering the French Parliament building. When he explained (very embarrassed and expecting trouble) that it was for his lunch, the guards smiled, gave him the knife back, and waved him through. I remember we admired how civilized the country was.
It seems like this should be super easy to spot by outfitting X-ray machines with computer vision that can compare shapes/outlines from the X-ray image with a massive catalog of 3D printed gun schematics. Of course this would only help with assembled guns, but it's a step in the right direction.