“If you don’t hit something vital, it isn’t going down regardless of penetration or the number of hits.”
More importantly, a criminal is going down for 15 seconds even if you hit the guy square in the heart with a .45.
A lot of bad things can happen in 15 seconds.
Defensive handgun rounds are all subjective. All I know is the wife with her Judge using the Federal 3” shells can put 25 .36 caliber lead balls (five with each shot) into a 12” circle at 15 feet faster than I can read this missive.
She can also put 14 .380 rounds from her Bersa Model 85 (13+1) into the a 12” circle at same range even faster.
She is also 70 years old, nuff said.