Yeah I'm not going to quote all that. The following is a PSA.
Gentlemen we need to talk about terminal ballistics and ammo, and why "Stopping Power" is silly to talk about in a home defense scenario.
Bullets only kill people one of two ways: 1. Drastic loss of blood pressure (bleed out/heart stopped) 2. Neurological kill (brain)
You do not have the luxury of waiting for them to bleed out in CQB ranges. You should assume that they will fight back until they can't. You need to shoot them until you achieve one of the above, which means either many holes, or one well placed shot. Bleed out matters much more as the range opens up, hitting a guy 500yds away who dies 15mins later is a pretty good deal. Same cannot be said when he can nearly reach you physically.
Rifle bullets typically behave one of or in combination of three ways when hitting a person (by design or otherwise). Fragmentation, deformation, and tumbling.
Fragmentation occurs with the rapid deceleration of the bullet, resulting in an explosion like burst into lots of tiny pieces.
Deformation occurs when the bullet meets resistance that reshapes it, deliberately or not.
Tumble (or lack thereof) occurs when the bullet changes, or technically adds, a new axis to its rotation.
M193 and Green tips are velocity dependent rounds that are designed to fragment well. Their performance diminishes as velocity does. But also of note, their penetrative depth also wildly affects the trajectory of those fragments. These give seemingly devastating wounds at high velocities, but lack predictable and dependable wound channels, which leads to the often touted stories of 5.56/.223 lacking stopping power (Tom Grieve) while simultaneously offering no shortage of one shot stops (Rittenhouse). Say you land a round in the thoracic cavity, maybe you explode his lung depending on your and his luck, maybe you put a .22 sized hole through it. Maybe one of those fragments nicks his heart, maybe several do.
You want good defensive ammo built to deform (like the hollow points in your conceal carry). Even with the (rather unpatriotic I might say) fixation on home defense ranges. Modern defensive rounds are built with more weight, imparting more energy and mass and to wound through much more predictable and uniform deformation, which leads to uniform fragmentation, much shallower in the intended target then ye old 55gr fmj. This leads to consistently more lethal rounds across all ranges, this means you hit the important things, statistically, in fewer rounds. It matters. If it didn't matter you wouldn't be holding a gun in that exact moment.
Tumble is a bit self explanatory, it is the least effective and reliable way to incur damage and mostly comes up at long range for 193 or m855 at long ranges or pistol calibers. Won't elaborate here.
Buy high grain modern defensive ammo and zero on it for the gun you keep in the bedroom.
Edit/PS: Please stop telling people to aim for the nuts/pelvis. The logic of this does not apply to you and is hardly even taught any more to the guys it does. Heads and hearts. Not "center mass". Heads, hearts.