onto the target. 7 hits to the chest in the span of one second, 90 ft lbs each, is a lot of tissue damage and shock for a man to have to deal with, and if it comes unawares, as most assasinations of course do, it's pretty likely to just collapse the guy on the spot. As vs lots of misses and poor hits with .45 ball, you can see why the canned .22 is often chosen, and why it works pretty well. Even without a can, a good .22 auto pistol has enough less blast and recoil to make the typical untrained guy pretty effective, and he can train a lot more with the 22 than he can the .45, of course, for the same money. He can come-by good .22 ammo a LOT easier too, in nearly any part of the world.