Hi @Bernadette82
Jess (sorry can't seam to tag?) has really good advice here.
24 hours in advance at least for instant book (you can still have the option for same day, but they have to request first so you can avoid suprises!)
Weeds out alot of iusses, same day bookings (especially locals) often have a bad rep.
If guns are an issue for you, could you put an extra rule saying no guns on your property? (Maybe worded to stay nuetral in your uniquely amerian debate over guns, " you don't provide correct storage in the room therefor would like to keep them off the property"?)
Also yeah, dropping off the gun at a police station is a good shout.