I hAve no experience with big Bears, or the 10MM. But one of the Norweigen Countries have a long range patrol force that has fairly regular run ins with Polar bears. The Glock 20 is their issued Sidearm
Yep, here it is...the Sirius Greenland Patrol. They also carry 1917 Enfields in 30/06.
http://en.wikipedia.org/wiki/Sl%C3%A6depatruljen_Sirius
VERY interesting! And IMO they are quite well armed and set up, both handgun and rifle wise.