The parameters are; it's a girl who does not like revolvers, and the question is; Glock20, can it work (10mm) on a grizz, not is it the best, but, is it possible, now, the bullet you posted would for sure work if placed well, but I can see that bullet is almost like armor piercing, which is usually not legal to hunt with that i know of, and the bullet you posted is also very good for penetration but it's the wrong caliber and firearm, the idea of the question is to explore the possibility of the 10mm hand loaded; as commercial loads are not available to best fit for grizz, and the user requested no other calibers be discussed, that does not mean I don't like that bullet you posted it's just not what the user asked, no offense. So to say that my suggestion of a 10mm loaded with 10.5 grains of blue dot and stuffed with a gold dot 180 grain bonded, seems to be the optimum load, based on the data i've seen, when one looks at available components that are loaded for 10mm that is, and to be honest, I'd never want to shoot a grizz with anything, because that grizz is 1,000 lbs of trouble I don't want to piss off, but if the bear ate your friend, or was feeding on your dog, then you might dump a mag or two into his nasal or occular cavity area, with what you have, be it a 10mm, then so be it, and if be it, be the gold dot 180 grainers which can penetrate the 10.5 inches necessary to destroy the brain, provided the round does not deflect,