3D-printed guns: Unleashing firepower minus rules

The threat of 3D-printed guns grew significantly with the emergence of the FGC-9 (“9” denotes its 9mm bullets), a futuristic-looking, semi-automatic pistol calibre carbine requiring no regulated components and fully DIY. About 80% could be made from plastic using a standard 3D printer, while the remaining metal parts could be fashioned from widely available steel tubes and springs.