Are private owners taking matters into their own hands really better? Do you really want hotel staff rooting and pawing through your bags (or x-raying them) whenever you check into a hotel? How about body scanners or magnetometer gates like in an airport? Every. Bloody. Time. You go out for a drink or a show, come back and have to stand in line and deal with that nonsense?

How would that even work in smaller hotels or motels with multiple entrances? What about landlords? If you rent a condo in a high-rise, should you be subject to a search whenever you walk into your own home with grocery bags?

That would end up basically being a privately-run police state. Or we could just make it more difficult for nutters to buy powerful weapons.

Plenty of states make getting a license a PiTA, and their laws pass the 2A test. No need to change the Constitution, just pass stricter licensing laws for the more powerful weapons.