I went with .45 thinking that it would be a all around reliable option, if I was forced to shoot through a door, windshield, car door or a large person or multiple large people, a .45 would inflict more damage than a 9mm or .40 or smaller calibers. I hate to say it this way but if I am forced to use a firearm instead of my mind to get out of a bad situation then the other person/persons probably should be killed.
txbroker, you might check out the following page http://www.theboxotruth.com/docs/buickot3.htm