If only one shot will hit, make mine a 45
that one shot hits in the same exact spot, a 9mm through the heart, major artery/vein, spine, brain beats a .45 that misses those vital areas.
the 115 grain 9mm Luger and the 230 grain .45 ACP have more than sufficient penetration to reach the vitals. The slight wounding advantage of the .45 ACP, is of minor importance.
Bottom line is, they both fall into the classification of service cartridges
, that is to say ones that are suited for Military and Police Duty. Either one does an okay job in that role. Whether the projectiles be FMJ, or expanding.