We could try using the Fermi estimation technique ("how many piano tuners are there in Chicago?") I have to agree with suresk people, out of all of the folks I

We could try using the Fermi estimation technique ("how many piano tuners are there in Chicago?") I have to agree with suresk people, out of all of the folks I know, the number of guns is either 0 or >1. I don't know anyone with just one gun. I suppose if you divided the number of people in a household by the number of guns you may get a number closer to 1, but that means assigning gun ownerships to babies.