A video showed the handgun being successfully test fired and the images have been viewed by hundreds of thousands of people on the internet. Instructions on how to make the gun can also be downloaded. It uses .380-calibre bullets made from plastic components and the firing pin is a single metal nail which may be too small to be picked up by metal detectors.
Last week the Staples chain said it would be stocking a 3D printer, the first major retailer in America to do so. The Cube 3D Printer costs US$1300.
According to the US Bureau of Alcohol, Tobacco, Firearms and Explosives, US citizens are allowed to make firearms for their own use but to make and sell guns they need a licence.
Cody Wilson, of Defence Distributed, says: "Gun control for us is a fantasy. In a way that people say you're being unrealistic about printing a gun, I think it's more unrealistic, especially going forward, to think you could ever control this technology."
Two Democratic congressmen from New York are also pushing for measures similar to the California one. It comes after a bill to tighten background checks on gun buyers failed to pass the US Senate last month.