He said "It doesn't matter which one you use, if you shoot them three times in the head."
That's not actually true. Jim Cirillo was fond of telling the story of two of his teammates, who were on their way into a stakeout when they got mugged.
When the dust settled, each of them had emptied their revolvers -- 6 shot and 5 shot, respectively -- into the bad guy at bad breath distance. All 11 rounds of .38 spl lodged in the suspect's head or neck.
The man was unconscious and looked dead. One of the officers stood over the body and radio'd in a description: "Suspect is a black male, appears to be, uh, uh, 32 years old --" Just then, the 'dead' guy sat up and said, "Sh-- man, I'm only 25!"
Then he asked for a handkerchief, because he had "something" in his nose. When he blew his nose, a bullet plopped out onto the sidewalk.
He walked to the ambulance.
There are no guarantees in a gunfight.
Zero, none, nada. There are things you can do to improve your odds and things you can do to make your odds worse. But if you go into it thinking, "This is how it's going to be..." you're likely to get bitten by something you never expected.
No magic bullets. No magic guns. No magic shot placements. Just some that work better than others, most of the time.