Looks like they are forcing folks to go to 1911 45ACP pistols whose mags only hold 7 rounds. It seems to me that one hit from a 45ACP slug is about 3 times more damaging than a 9mm and maybe twice as damaging than a 40 S&W.
Simple not the case. Pistol rounds essentially only make a permanent wound channel. A .45 has is .096 inches larger. Barely a tenth of an inch.
Shot placement means everything. Even a heart shot from a .45 gives a determined attacker 5-10 seconds to shoot, stab or beat you.
Having more rounds in the mag gives you a better chance of hitting the noggin or CNS. This is why the FBI went back to 9mm.