SOME 9mm loads have considerably more ballistic energy than some .45 loads and they utilize that energy better, too. The corbon 100 gr 9mm has 1500 fps, which means 500 ft lbs, from a 5" barrel. Put a 230 gr ball .45 rd in a 3.5" barrel, and it gets a mere 720 fps, for barely over 250 ft lbs. furthermore, that low velocity (with 5" barrels, too, 850 fps) wont expand the jhp .45 in flesh. so it wastes 1/3rd or more of its power on the far side of the attacker. So dont kid yourself about the .45, or the slow, 180 gr .40's, as being superior to the 9mm. They are not. the 165 gr .45 Corbon and 135 gr .40's, yes, those are superior.