Downloading weapons...?



A little education for you.


See the issue?

No issue at all. Anyone can buy a gun from a non-dealer without any of said checks or registrations. In most states citizens who can own guns can also manufacture a limited number for their own personal use. All of this is and should be legal.
 
I don't think they're too worried about a home-made shotgun. Besides, anyone with pliers and a hammer has a shotgun. I think they're more worried about the more technical fully automated weapons. - Or the very high caliber weapons that are not legal to own.

The majority of submachine guns used in ww2 by the UK and Russia were made by children under the age of 16 with hand tools and stamped metal for $25 or less.

I've seen a few examples of submachine guns made from home depot sourced parts for under a hundred USD, including a 'silencer'.