My friend and i both agree and disagree on the subject of stopping power on the 9mm vs 45 acp. If both were using ball ammo i agree the the 45 acp has better stopping power. But put 9mm +P i believe has better stopping power then the 45 acp. Like the old disagreement which is better a big slow heavy bullet vs a faster lighter bullet which has better stopping power. I do carry 45 acp and 9mm pistols but 16 rounds vs 8 rounds makes you think which is better to carry.