content: So in case you don't realize (because many don't) The part being 3D printed here is the part that is regulated. It's the part with the serial number and the part that is considered to be "the gun". Every other part of the gun is freely purchasable by anyone of any age without a license or the need to have a serial number on it (or any other identifiable markings). So when we think "3D printing a gun" people are printing the whole thing! No, it's just the receiver or the upper or whatever part of a specific firearm that is the regulated controlled part. This is a way to get around the illegal restrictions on firearms and the constitution, and since all other parts can be bought literally anywhere or even made for most guns easily enough, this is a wonderful thing in my mind.