I would guess that with the right placement that it would kill a grizzly but honestly, I wouldn't get one for home protection. In a protection situation you want something that you have an intinmate knowledge of the weapon and how accurate it is going to be for you and that means time on the range. The bullet will do the job but whether or not you have gusto or cash for that matter that it would take to do it may be another question. Besides these factors, I say if your going to go big for grizz then go big. SW makes a nice 2" barrel model just for this in 500sw. Thats the caliber I'd go with.