I would think with that gun coupled with a powerful, maximum damage type of round like I mentioned, that ought to do the trick. From everything I've read, the best spot to aim for is at the back of the roof of the mouth, the soft palate, at about a 15⁰ - 20⁰ upward angle, so as to try and take out the brain stem. I've heard of others wanting to shoot themselves in their heart. It's probably effective, but not sure how instantaneous it is.