be pointless to shoot men with .45 acp. .72" 12 ga slug has 4x the frontal area of a .45, and 440 grs, at 1300 fps has 3x the momentum of the 330 gr, 800fps. .45, so the .45 has 1/12th the momentum-area "factor" of the 12 ga. So if the .45 is even remotely 'enough" than the 12 ga is WAY overkill on men. The fact is, tho, that the better jhp's, like the 160 gr powerball,at 1200 fps, do a pretty fair job of stopping men. Yes, there's been RARE cases of the 12 ga slug's not stopping men with a chest hit, but they are like 1 in 100 or less frequency.