Sweet Shooter, there's a difference between a psychological stop (your "change a guys mind") and a physiological stop (hence my "determined and aggressive BG").
With a psychological stop, caliber & bullet used are moot as the BG *chooses* to end the attack for whatever reason (doesn't want to get shot, feels pain, sees his own blood, etc).
With a physiological stop, the attack ends because the BG's brain shuts down from either direct damage to the CNS or oxygen deprivation due to bleedout regardless of the BG's desire to continue the attack.
There are numerous cases where multiple handgun hits have failed to stop a determined attacker (Platt in the infamous Miami Shootout comes to mind) so your "twaddle" comment is just that: twaddle that's not based on objective reality.
Please explain the mechanism by which the "energy" you referred can "change a guy's mind" if he's aggressive and determined.
Please explain the difference between "sufficient" and "appropriate" penetration when it comes to self defense. Sufficient is enough to reach the vitals, the contrary being insufficient to reach the vitals. Where does "appropriate" fit in here?
I respectfully disagree with your comment "The projectile behavior in soft tissue is the single most important aspect of the entire equation." The single most important aspect of the equation is shot placement. The most effective bullet in existence has no effect if it misses the target.
Tomac