"When you're up the creek, use Mozambique."
Sorry, guys, I don't even trust 'big holes.' There are numerous reports of people simply full of adrenaline that took over a dozen hits and kept on going.
Hitting some major boiler room part of the physiology is the only guarantee.
Under duress, your aim might not be what you'd like in a perfect world. The Mozambique drill is a classic because it works.
It ain't rocket science. Even Euc should be able to hit a grapefruit sitting atop a volley ball. Practice, practice, practice, tactical reload, practice.