How do you regulate a piece of plastic?
Remember the two liter soda bottle silencer from thirty years ago? All they could ban was the adapter.
Anyone remember 1968 when Bobby Kennedy was murdered? At the same time the Feds raided a secret unlicensed sub-machine gun making company in Southern California. It was said the unmarked sub machine guns were being shipped to South America. It was also claimed LBJ knew and secretly approved the manufacture of these.
It’s a false piece of nonsense. A person so motivated can make “bump” functionality a lot cheaper than the 200$ bump stocks. YouTube shows us how.