In this episode of CBS’ S.W.A.T. (Season 5, Episode 19, May 1, 2022), parts for a plastic gun are smuggled onto a plane and then used by a criminal to shoot a U.S. Marshall. The plastic gun is then given to one of the other plane’s hijackers who attempts to shoot the S.W.A.T. members as they rescue the plane’s passengers and arrest the criminals.
The problem with this episode is that while gun control advocates are constantly worrying about plastic guns being smuggled through airport security, urban legends are a poor basis for making public policy. We have searched, but we can’t find any news stories about high-tech plastic weapons being used in the real world to hijack airplanes or to commit any other crimes, because — to repeat — they do not, at the moment, exist.
Might you be lucky to successfully fire one shot of a very small caliber bullet? Possibly, but you are taking a real risk. This gun is shown being fired four times with a large caliber bullet and no problem. Here is a news story on the issue:
Aysha M., “3D printed guns: where are we now?” 3D Natives, September 2, 2020.
As for the materials, in order to manufacture a gun with an FDM 3D printer, one can choose between several types of thermoplastics. However, it is usually either PLA or ABS that is used for this purpose. But even these thermoplastics are not perfect for the fabrication of a functional gun. PLA is softer, so a part made from it typically deforms very quickly. ABS is harder, but it only means that it will crack and break rather than deform. Therefore, the user can usually only fire one bullet before a thermoplastic part breaks – the explosive force of firing a bullet being too powerful. For example, in 2013, a police department in Australia tested out a 3D printed gun: they were able to fire a 17 centimeters bullet, but the plastic immediately exploded once the bullet was discharged.
This isn’t the first time that CBS has tried scaring people about plastic guns.
Here is a video on Hollywood’s bias against guns.