The answer is surprisingly true, and false at the same time. It is false because a .45 has more kinetic energy than a .22, and it is true because statistically a .45 has an incapacitation rate of 51% with one shot to the torso. And the .22 has 60% incapacitation rate with a one shot to the torso. Based on a ten year study in shootings and the calibers used. How can this be? First off like all statistics the outcome can very by how the input was collected and sorted. For example the people shooting the .22,s could be better marksmen than the people with the .45’s. these results were collect as they were reported in the real world. Not in a vacuum of a lab. But the results are very telling none the less. My take is no mater what caliber you are shot with, when you get shot, half the time you will decide to call it quits. Whether the wound is fatal or not. Now we couple this information with the fact that most confrontations are ended with the brandishing of a weapon, I don’t have the stats on this but I will challenge it is between ninety and ninety five percent, when a weapon is drawn to stop aggression, and never fired. If you have facts to dispute this claim please share them. Back to my point if we assume that 90% (totally my made up number) of the time you draw your weapon in self defense you don’t have to fire it and you add the fact that half the time any caliber will do, we are left with a 2.5% window where caliber makes a difference. Perhaps a vital life and death difference I will concede that. 97.5% chance that a .22 will get the job done is good enough for me. CTHorner.