it depends on your purpose. for hunting black bear, too small. for defensive use against black bear, i think it is perfect. BUT... in a 610 i think it is at a disadvantage. the real advantage of the 10mm is capacity of the autos. with a 610, you only get 6 shots. with that restriction, unquestionably a 41, 44,480, or 454 is way better suited.
so if you are planning on going out to hunt a blackie, get a bigger caliber. if you are using it as a defensive only gun, it beats fingernails. and if you are using it as a defensive only weapon, i would load the first two hollowpoints and the next four with a 200grain hardcast lead bullet.
my bro had a really bad experience with a black bear last year. he carries a glock 10mm with two 15 round magazines now at all times while in the wild.
two weekends ago we were floating a small river for trout. we came around a corner and a cub went running up a tree on the bank about 25 feet away. while we floated by, his glock and my smith were drawn and pointed at the bank the entire time until we were a good 100 yards downstream. and i must admit, the 357 felt a tad small in my hands at the time. we load his 10 with a mix of 180 grain flat point hardcast and 180 grain xtp's on the top of the mag (first in the pipe).
hopefully we can stay in the land of hypothetical and never have to test it out. we both love black bear and are fascinated with them. we have some here that go well over 600#. i have encountered five this year so far. last year i was within 80 yards of a 400# mamma and FOUR of her cubs; while unarmed! she stood there looking at me and the cubs crossed the road, one by one. i sat really still, and when the cubs were gone, she turned and followed them. awesome! i will remember that forever.
if your intention is to hunt them, use a larger caliber. and for hunting, forget using hollow points. hardcast all the way.