Skadoosh and 481 you are missing my point.
It is just as much luck than skill where bullets land. A (gun) fight is dynamic, it is not static. I have seen people shot and killed and wounded with many common calibers. Low power rounds do unpredictable things in people. I went to one shooting and the guy answered the door with a 380 bullet stuck in his forehead, I have also seen major bones shattered by 380's.
When you get into the Hot 9mm's and the magnums they are MUCH more predictable. Lots of cops have been killed by 25 ACP's, it happens.
In the case of our mommy, (according to media reports) she shot him through both lungs, the liver, the face and he STILL drove away after she bluffed him into thinking she had more rounds available and escaped. How much better shot placement do you want? If the bullet lacks the power to disrupt the CNS ie; penetrate the skull or lacks the power to do enough tissue damage to achieve "rapid blood pressure loss" then you are out of luck.
There have been documented failures with every caliber. That is why I carry the most powerful gun I can shoot well and conceal. It may not be much, but I will take any advantage I can get, no matter how slight.
My rifle and pistol are tools, I am the weapon.