Тест распечатанного короткоствола: http://www.theverge.com/2013/5/6/4304164/video-of-defense-distributed-liberator-3d-printed-gun-test
"Forbes reports that one secret behind the gun's structural integrity may be that the barrel has been treated with "a jar of acetone vaporized with a pan of water and a camp stove," which is said to reduce friction by slightly smoothing the bore. The Liberator is made from 16 parts, 15 of which were fabricated with a Stratasys 3D printer, and one non-functional metal part helps the gun comply with the Undetectable Firearms Act."