At defensive ranges, a 357 mag is more than adequate for bear. With a heavy, cast bullet you will get about 2 feet of penetration behind 650+ ft. lbs on energy. Hit a bear anywhere in the head/spine, and you' ll drop him immediately b/c brain or spinal cord will be annihilated. Furthermore, hit a shoulder with this load (corbon 200 gr. cast +P), and you will break the shoulder and enter the body cavity.