One of the Holy Grails of the gunny world is "stopping power".
Arcane formulas combining bullet weight, velocity and diametre in various proportions are proposed, established, fretted over and adopted -- or discarded -- in search of a pistol/round combination that will "guarantee" that the user will emerge victorious in an armed confrontation. And choices once made are defended with religious fervor.
To my mind, none of these formulas are capable of quantifying the most important part of stopping power.
This is not to say that your choice of sidearm and your choice of calibre aren't important in your search for "stopping power" ... but there is another variable that is much more important than bullet size and velocity.
It doesn't matter how big a hole the bullet makes ... if you don't carry the gun that fires it.
It doesn't matter how fast that bullet is going ... if you never practice with the gun that fires it.
I see that I have lost some of my Gentle Readers. Allow me to explain.
One of my training officers carried a Colt Lightweight Commander in .41 Avenger. This round was -- and is, to the best of my knowledge -- a custom affair, involving a .45 Winchester Magnum case trimmed to .45ACP length and then necked down to .410 inches. From what I've read about the .41 Avenger, it is a perfectly adequate self-defence round.
This officer bought the pistol in the late 1980's, and fifty rounds of the bottle-necked ammunition came with it.
In 1994, he still had 36 rounds left of the original 50. In ten-plus years of carry -- patrol and otherwise -- he had only fired two magazines worth of ammunition out of that pistol.
Now, some of the canyons that dot the Panhandle caprock are full of prickly pear cactus. On slow patrol days, it wasn't unusual for gun-savvy officers to utilize these plants for impromptu shooting challenges of the "Right, ten yards, low, two fruits -- GO!" sort.
The one time we were able to chivvy this officer into shooting with us -- he was unable to consistently hit a prickly pear pad at seven yards.
Folks, .410 inches; 170 grains; 1100 feet per second looks almighty good on paper -- but if you haven't practiced enough to hit what you're aiming at ... what good are those numbers doing you, exactly?
Another gentleman of my acquaintance -- not a peace officer, but a gunny type -- had become enamoured of the 10mm. My paw to Freyja, the man had a ten-minute speech -- spiced with multiple quotes from Colonel Jeff Cooper (pbuh) -- regarding the merits of the 10x25mm.
Not being able to get his paws upon Messers Dornaus and Dixon's Bren Ten pistol, this gentleman had settled for the next best thing: a Smith and Wesson 1076 "FBI Special". And -- as with the round it fired -- he would happily opine at length as to the man-stopping abilities of that particular pistol.
The thing is, didn't matter where he was, what time of day it was, or what he was doing -- if you asked to see this wonder of gunfighting tools ... he'd go and get it out of the safe.
.400 inches; 200 grains; 1200 feet per second are "stopping power" stats you can't argue with -- but if they're in the gun safe at home when you're face-to-bad-breath with a critter in the mall parking lot ... what bloody good are those statistics doing you, exactly?
In contrast, allow me to introduce an older gentleman. He carries a three-inch Smith and Wesson revolver in .38 Special.
Now, most tactically-aware gunnies will be quick to tell you that the .38 Special is towards the low-end of the so-called "stopping power" spectrum. Matter-of-fact, most would tell you that .358 inches; 158 grains and 900 feet per second is the bare minimum.
Thing is, that old gentleman shoots a minimum of 200 rounds out of that pistol every month. He plinks dirt clods and charcoal briquettes with it; he hunts jackrabbits on his oil lease and turtles in his stock tank with it; he's taught his children, grandchildren and multiple acquaintances to shoot with it; and he shoots in several formal and informal matches each year with it.
That pistol is a part of him. He puts it on each morning, and takes it off each evening. The bluing has etched away from the thousands of draws from leather he's practiced; and the grips are worn to match his hands.
If the eco-friendly fertilizer hits the rotating, oscillating, vector-flow cooling unit that .38 is not going to be sitting useless in a gun cabinet: it's going to be where it's been for the past several decades -- because he carries it.
He's not going to flinch, he's not going to fumble his draw or muff his shot; and each round is going to go exactly where he wants it to -- because he practices with it.
That, Gentle Readers, is stopping power.