Folks have a weird habit of splitting hairs when it comes to survival. What difference does it make whether a stop is psychological or physiological?
What really matters is results, so regardless of whether it be due to incapacitating physiological damage to vital organs or just a potent combination of pain and fear, if one particular cartridge has a higher volume of stopping a threat than others, then that's all that really matters.
In other words, even if factually speaking, more thugs cease attacking someone with say a .357 Magnum than a 9mm Luger simply because the gun emits a more intimidating muzzle flash and report when fired, what difference does it make?
For the center mass/chest hit with 12 gauge double OO buck it’s darn near always a one shot stop but I have heard of one case where it wasn’t but I don’t know how accurate the data is.
Which brings me to my next point, another thing folks have a weird habit of doing when it comes to self-defense is expecting that every last thug on Earth is under the influence of narcotics so strong that their ability to feel pain is inhibited, which while that may be a possibility, there's always one vital factor or perhaps some misunderstanding at work here.
While certain narcotics can indeed inhibit pain, fear is another factor, and I have personally had the misfortune of being exposed to enough people who were either high or suffering from withdrawal symptoms to safely say that more often than not, druggies are jumpy, scare extremely easily, and are often completely paranoid. As a result, I am confident that getting shreaded to bits by buckshot would likely be psychologically traumatic enough for them that however many seconds they may have left to live, they're probably too freaked out by the sight of all their structurally superfluous new orifices leaking vital fluid at an alarming rate to be in a state of mind to continue attacking.
Furthermore, folks who are strung out on drugs usually have an elevated heart rate and blood pressure by default, so you can imagine how much faster their heart would be going during a violent confrontation, especially ones in which bullets are flying in their direction, and even more so once they've been shot, ergo while a normal human being might theoretically be able to to remain physically active for a moment after a bullet has torn through their heart, it would seem highly likely that said length of time would be considerably less for one who's heart is beating a mile a minute.
Last but certainly not least, I would like to once again request detailed, verifiable accounts of these situations in which someone was shot through the heart, yet kept on attacking, essentially ones in which the attacker remained active long enough to actually inflict significant bodily harm to their intended victim before succumbing to their wounds.
Honestly, I'm hearing a lot of "ifs and buts" here, but so far nobody has presented any evidence to support these ifs and/or buts. So unless you've actually got something to support these claims beyond words, please refrain from making any further bold statements like how 9mm FMJ is just as good or better than larger caliber expanding bullets, let alone a barrage of bullets of equal size such as a 000 Buck shotshell.