Target practice.
Let's see...3 and 1/2 inch magnum number four turkey load or my new .410, with the rifled barrel and a three inch slug?
Or maybe my new Springfield in .30 caliber.
Hell, I might even invest in a Barrett for this.
In any event, it has to get close enough and if I know the ATF chicken-s^^ts, they'll stay well out of range whilst they spy and generally shred a few more of our Constitutional rights.
You might need a little more range than the buckshot will give you. But if you fit that 30 cal up with a 22MM grenade launcher and use a practice grenade to trail a light cord you can snag a lot more little propellers——just trying to help-—carry on-—semper fi.