One of our local LEOs was executing a search warrant, and was forced to shoot a bad guy. Our LEO was armed with a 357 Sig with 125 grain Speer Gold Dot ammo. The bad guy took six rounds in the chest before stopping. All six rounds penetrated the bad guy, went through a couple of walls and exited the house almost striking an officer outside. I don't believe any of the rounds expanded. Something you might want to consider if you chose the 357 Sig for self defense.