Mike,
The advice regarding 150gr. - 165gr. bullets are right on. Those referencing older norms haven't been keeping up to date with how "modern" bullet construction advances have improved terminal results. The old 180gr. are now the new 150-165gr. bullets.
If you can't pole-axe a Mule derer with A 165gr. bullet out of a 300 Weatherby, you wouldn't be able to kill it with an M40 grenade.