Weeeeelllllll yer not gonna like my answer. At our fly in camp to an island near kodiak we stayed at a "bed and breakfast" style structure that had been built up from an old fishery. The crapper was still rustic to say the least and near the door was about three or four of the oldest ugliest , rusted up 12 gauge pump guns ranging from old model 12's to the Mossburgs and 870's.
The exterior of the firearms was either rusted or spray painted with rustoleium. But they functioned flawless. When one went out fishing or just to the outhouse ya took one of the "working" camp shotguns. First round from the magazine tube was a number 9 bird shot which we were "instructed by the local guide" to put down just in front of the bears paws if s/he did'nt want to leave ya once s/he knew ya weren't food per se..... Ya stung the bear in the tenderest part of their body. I never had to do such but it was a common practice to sting or dust the bear with a very light Number 9 birdshot.
Of course the rest of the rounds were slugs.......:o)
Stay safe !