Any half decent workshop can make a better "gun" than any 3D printer available to the general public can since the year dot. Heck, around this parts technical student gangs shoot at each other with "guns" that are little more than a steel pipe with a screw-on breech, pop in a round, aim in the very general direction of the target, bang.

Making something that can shoot a bullet is not a terribly complicated feat of engineering, making something that you can wield, aim and use repeatedly without it blowing up in your face is the difficult thing. With 3D printers the last part is the main stumbling block, you just can't make a gun barrel out of thermoplastics, fuggedaboutit. So in the end this guy had something that looked like a gun(s), that could go bang bang shooting blanks, little more than a cap gun you can buy in a toy shop.