A TFB reader recently 3D Printed 9mm caliber bullets and loaded them 9mm Luger/Parabellum cases with subsonic and supersonic loads. The bullets were printed with PLA, a bio-plastic made from corn starch in the USA or sugar cane elsewhere in the world. PLA is commonly used in 3D printers as an alternative to ABS plastic (think lego bricks). It is easier to print (at least in my experience) than ABS requiring lower temperatures and it has a pleasant non-toxic smell.
The bullets printed weigh just 13 grain, about 10% of the weight of a regular 9mm bullet. This puts them in a “less lethal” category along with rubber bullets. The subsonic variant of this round (loaded with 1 grain of N320 powder) would have had under 31 ft/lbs of muzzle energy, less than a third of a .22 LR round. Still, I am sure it would sure hurt like crazy if one of these hit someone in the chest.
A supersonic load had the same 13 gr bullet but backed with 3.8 grain of N320. The velocity was not tested, nor was the accuracy.
Watch the 3D bullets being made and fired from a pistol …
Next I think they should try printing a bullet with channel through the bullet for air to pass creating a whistling noise.