The armed forces don't have the lethal encounter market cornered.
Furthermore one does not need to take gunfire to qualify for an opinion on their choices for self protection equipment.

Also the ballistic fantasy of that pistol equaling 40gr 223 @ 400yds is nonesense.
First off expect 1300fpsMV from the featured pistol (numerous chrono results)
Expect 1900fps from the 223 @ 400yds (typical 40gr varmint load)

...and I'd stand behind one .45acp any day - although I will and do at times carry a rimfire in place of *nothing*, and I would not stand in front of a .22