|This full-scale Schlieren image shows the discharge of a .44 Magnum revolver.|
Lethality comes in threes, you need to accurately hit your target. The "center of mass" hold for pistol shooters is fine for a high probability of lethal effects, but it is almost a guarantee that a center mass hit will not "stop" an attacker. To stop an attacker you have to get a central nervous system shot, brain or spinal column, to get a guaranteed stop.Read the rest and the links at the beginning of his post.
Shot placement. Shot placement. Shot placement.