If you run a gun club where people can safely fire fully-auto weapons in a controlled environment, you are allowed to own them and supervise people firing them.

This is not an easy or inexpensive thing to set up.

I shot a documentary about a guy doing just that in NE Scotland, about 20 years ago, and while his range is still in business I don't think he has ever cleared the tape for redistribution - it was a "here's what you spent your money on" for the investors.