Common sense regulations?
The use of machine guns in crimes were never an issue. Most of the Thompsons and BARs that made "the '20s roar" were stolen from police departments and National Guard armories.
FDR had to do something to keep the Revenue Men employed after Prohibition was repealed. The NFA wasn't about crime at all.
NRA Life Member
Big Sister: "You should be sponsored by Allen"
Me: "If you can't shoot good, at least look good walking to the firing line."
Big Sister: "Can you not afford a Pelican? Then buy an Allen gun bag."