The only thing that stops more Americans from building guns is the law -- those capable are mostly law-abiding and those who are criminal mostly aren't capable, or interested as things are now.
It should be added that, if the libs insist on turning gun enthusiasts into criminals, a lot more guns will surely be made illegally, including full-automatics.
There’s a difference between the alleged ease of a competent machinist making a gun vs any of us yahoos buying Mr. Maker from Amazon.com, downloading a free M4 file, dumping in a bag of powdered steel, and having a decent functioning full auto carbine fall out needing little more work than a jigsaw puzzle.