I am aware of 10mm pistols, and for a couple of years was considering buying a 1911-type in 10mm as being the ideal bear gun. But I sort of decided to stay with the 1911 in .45 ACP. I'm unlikely to see another bear outside my house, but possible; but I'm unlikely to be armed anyway, just taking out the trash or similar. Should that rare occasion happen with no pistol I guess I'm lunch, because I'm unlikely to have a Professional Hunter watching my back. But the one I did see ran the other direction faster than I could run back to the porch!
DG