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FDR had to do something to keep the Revenue Men employed after Prohibition was repealed.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
"Boy Scout Problem #18: Living with the fear that one day someone will find out you can't tie anything more complicated than a square knot."