Examining the effects of 3D printed projectiles on firearm identification

In recent years, 3D printers have become more affordable for the average consumer to purchase, and new printers require less user input, making the process accessible to anyone who can download files online. Due to these factors, these printers are being used to manufacture firearms and firearm components privately. In 2023, New York began requiring background checks for anyone purchasing ammunition within the State, which may increase interest in manufacturing ammunition at home to bypass these background checks. This study addresses this potential problem by specifically examining 3D printed projectiles. It was found that 3D printed projectiles are suitable for use in a firearm and will acquire the class characteristics and individual characteristics of the rifling. These marks may enable the identification of a bullet to a specific firearm. However, the markings are hard to visualize due to the filament material, but can be enhanced by casting the projectile. The projectiles also exhibited reduced markings when compared with conventional bullets most likely due to the bearing surface of the projectile melting during the firing process. However, it was found that reducing the amount of propellant allowed more markings to be retained for comparison. Further testing revealed that the projectiles could perforate common obstacles, including drywall, plywood, and automotive glass, and penetrate a bulletproof vest. The projectiles also acquired markings from the printer's build plate, which can be used to connect the projectile back to the build plate. These findings reveal the similarities between 3D printed projectiles and conventional bullets.