Any idiot with a drill, a chunk of metal, and a few rubber bands can make a one shot zip gun over a weekend.
any half decent machinist can produce a sten in an afternoon with bike parts. Another afternoon for a suppressor.
not safe or accurate, but it will work.
Like someone stated about drug dealers, making it illegal and throwing a few in jail won't slow criminals down. Think how much a $50 AK bought in sub-saharan Africa would be worth once it was walked across the US-Mexico border? I believe a total ban would limit the number of semi-autos and repeaters, but significantly increase the number of full auto rifles in the US b/c it would create a demand for the network to be created. Once it is in place it will grow larger and larger.