From "
Geek with a Gun"
There are a few arguments in the firearms world that just never seem
to die. “AK vs AR” is probably the most famous, and we might try to
tackle that at some point when I feel like beating my head against a
brick wall for 5000 words. Anyway, second only to that is “9mm vs
.45ACP”, and that’s the one we’re going to look at today. The argument
more generally is about “light and fast” vs “slow and heavy” as it
pertains to handgun bullets. So we’re going to examine this whole
concept, look at some of the ideas people have had about it, link to a
couple of articles I’ve found on the topic, and then finish up with my
own thoughts.
A caveat: This article is all about defensive shooting. If you have
no interest in using firearms for defense, this info won’t really mean
much to you. It might even hurt your feelings or make you uncomfortable.
Fair warning.
Let’s start by defining a few terms. “Stopping Power”, as I use it,
is not the same as “Knockdown Power”, a concept you might have heard of
before. “Knockdown Power”, or the ability of a bullet to physically
knock an attacker to the ground, is a silly idea when it comes to
handguns. Here’s some relevant physics: Every action has an equal and
opposite reaction. What this means for us is that the energy pushing the
bullet forward is matched by energy pushing backwards against the gun.
As my friend Isaac reminded me yesterday, “Force” is equal to mass times
acceleration, and acceleration is change in velocity over change in
time. I don’t want to get too off topic here, but what that means is
that you feel less force when you slowly accelerate your car to 60 MPH
than when it comes to a sudden stop against a tree. The mass of the car
stays the same, so the difference comes in how fast you go from 0-60 vs
how fast you go from 60-0. Same thing applies to bullets, but the mass
of the bullet isn’t equal to the mass of the gun plus your arms,
shoulders, chest, etc. so the same energy pushing the bullet will push
that bullet faster or farther than it will push you. Make sense? So, if
you think your bullet is going to knock down a bad guy, you’d better be
shooting a gun that packs a heck of a whollop. That means big rifles,
maybe big shotguns. Maybe. Even then, it really depends on how quickly
the bullet changes velocity in the target. Even a big round that goes
straight through someone without slowing down much isn’t exerting a lot
of force (not a significant change in velocity of the bullet over time).
A big round, moving very fast, that hits an armored plate in a vest
might knock someone down because the bullet goes from real fast to a
complete stop very quickly against that plate. All clear? Okay, so if
we’re talking handguns (except maybe some giant-ass hand cannon like the
S&W 500 magnum), and we’re not talking about people wearing armored
plates, we’re not even close to anything that is going to exert enough
force on a body to knock it down. The rounds, once they penetrate the
body, will begin slowing down, but they don’t stop immediately so the
change in velocity is happening over a longer period of time than when
the bullet hits an armored plate. The size and shape of the round and
what it encounters along its path will determine how much it slows down
inside the body. This is why expanding rounds are more effective than
ball ammo. When a hollowpoint expands, it increases surface area, which
means it will slow down more quickly, exerting more force.
If someone starts talking like a regular .45 ACP hardball round shot
into an unarmored attacker is going to have “Knockdown Power”, they’ve
just confirmed that they are not your best source for firearms info.
“Stopping Power”, however, is the ability of a bullet to cause someone
to cease aggressive action. Maybe that means they run away, maybe it
means they just stop moving towards you but remain upright, or maybe
they actually do fall to the ground? That’s fine, but we need to be
clear that the bullet is not
knocking these people down. That’s
a meaningful distinction. It’s important because Hollywood likes to
show dudes getting shot and flying backwards through plate glass
windows. Real bullets don’t do that. If you’re in a defensive shooting
and you expect that your rounds will cause a violent, visible response
in your target, you will likely be disappointed. Many, many people who
shoot someone in self defense don’t even think they hit the person,
because there’s so little immediate physical reaction. No flying
backwards with limbs flailing, no explosion of blood from the entry
wound. That’s what you need to be prepared for, rather than thinking
your gun has “knockdown power” and one round is going to put your
attacker on the pavement whether he likes it or not.
Now let’s talk
about what actually needs to happen in order to get someone to stop
attacking you.
There are three (maybe four) ways to get someone to cease aggressive
action. One is what we call a “psychological stop.” This means that the
attacker still has the physical ability to attack, but has stopped
because they are choosing, consciously or unconsciously, to stop. This
could be because they’ve got extra holes in them now and have decided
that they don’t want any more of them. It could just be that they are in
pain, and choose to stop to avoid any further pain. These stops are
very common, but unreliable. Even a slap to the face could be enough to
stop some attackers, if they’re not particularly invested in the attack.
Does that mean that a slap to the face is your best defense? Obviously
not. The next two ways are really one way, but we’ll split them out for
clarity.
The first is massive bleeding leading to unconsciousness. If
the body loses a sufficient volume of blood, there will no longer be
sufficient pressure to get the blood into the brain to keep the whole
thing moving. Since the brain is still the big kahuna in this scenario,
the “massive bleeding” stop is still essentially a central nervous
system (CNS) stop. Anyway, this is why people are generally advised to
shoot for the “high center chest” area of an attacker. There are a lot
of bleedy bits in there. More importantly, there are bleedy bits that
are big enough and important enough that if they are damaged,
unconsciousness should follow relatively quickly. Unconsciousness due to
blood loss would be a physiological stop. Once a person loses enough
blood, they’re going to stop attacking no matter how dedicated they are.
How much blood a given person has to lose to fall unconscious is an
unknown, unfortunately. And as you’ve probably heard, there’s generally
enough oxygen in the brain to continue voluntary function for 10-15
seconds, even if the heart were to suddenly disappear entirely.
The
third way to get a stop is with direct damage to the CNS, meaning the
brain or spinal cord, generally. This can provide the most effective
stop, as it is possible to get a “puppet with the strings cut” response.
Police snipers, I’m told, train to hit the brain stem so that there
isn’t even the possibility for a reflexive trigger pull as the body is
falling. Direct damage to the CNS means that signals from the brain no
longer reach the muscles. Voluntary physical action within the affected
systems is no longer possible, and the effect is immediate. So that’s a
good thing, but it’s almost as if your body knows how important these
parts are and surrounds them with tough bone. Yeah, it’s a bummer. So
while CNS shots are super effective, they’re also harder to make.
The
maybe fourth stop is a skeletal stop, I guess you’d call it. The idea is
that bones and muscles work together to allow movement. A bullet fired
into bone could cause that bone to cease providing a stable platform for
the muscles to work against, thereby disallowing voluntary movement
with the affected body part(s). An example of this is the “pelvic
girdle” shot, advocated by some people in the defense world.
Essentially, a gunshot to the pelvis is supposed to shatter the pelvic
bone, which will render the attacker unable to use his leg(s). Here’s
why this is a maybe. First off, I’ve heard from several knowledgeable
sources that handgun rounds do not shatter the pelvis. They merely poke
holes in it. Also, if your attacker has a ranged weapon, having him on
the ground at distance from you isn’t actually rendering him incapable
of causing you further harm. It might just be making him a smaller
target and giving him a more stable shooting platform! So that’s why
it’s a maybe. It’s possible that a shot to a certain skeletal structure
could do sufficient damage to disallow movement of the limb, but it’s
nothing close to a guarantee.
Okay, so those are your three (maybe four) means to get an attacker
to stop attacking. When I talk about stopping power here, I’m talking
about the ability for a given round to achieve the goal of stopping an
attack by means of one or more of those mechanisms. Now to be clear,
every single firearm that I’m aware of has the physical ability to
achieve all of these stops (except the maybe fourth one, which is
another reason why it’s a maybe). Even the lowly .22LR has sufficient
power to penetrate into the chest cavity and damage the aorta, or to
damage the carotid artery in the neck, and it could certainly damage the
CNS if fired into the right spot. As for psychological stops, we’ve
already explained that almost any physical stimulus can achieve one if
the attacker is really not all that into the attack. So clearly, any
firearm will do that job if the attacker cooperates.
I’ve now spent over 1000 words just getting to the big point here: It
really doesn’t much matter what handgun caliber you use. All of them
are functionally identical, especially as compared to rifles and
shotguns. Handguns are inherently underpowered tools, and the
differences between them are very small when compared to the difference
between handguns generally and rifles or shotguns generally. There is
one caveat to this, though. I think that it’s important to use a handgun
round with significant penetrating power. While a .22, .25 or .32 can
potentially cause enough damage to vital organs to produce a stop,
they’re also much more likely to be stymied by heavy clothing, distance,
intervening materials (wallboard, windows, etc.). So my personal
opinion, and take this for what it is, is that your primary carry gun
should be something in .38 SPL or better (Maybe .380? That’s borderline
in my opinion). If you want to carry a tiny pocket gun for backup that’s
chambered in .22, .25, or .32 then I think that’s okay. Chances are
very good that 2-3 good hits from even a “mouse gun” would be enough to
stop any but the most dedicated attackers. However, as defensive
shooters we’re not too keen on putting our faith into “chances are”, as a
rule. This is also where we need to quickly explain the difference
between a gunshot wound being lethal and stopping the threat. As
defensive shooters we are not shooting anyone to kill them. We are
shooting to stop them from killing us or our families. If the attacker
won’t stop until lethal damage is caused, then lethal damage,
unfortunately, is required. Keep in mind, however, that just because
something is lethal doesn’t mean it will necessarily stop an attack. A
.22LR round the the heart might kill the attacker in a few days, but it
might not be doing enough damage, quickly enough, to cause the attacker
to stop in the timeframe necessary to save your life. That timeframe is
generally “Right Now” in case you were wondering. Attacks happen
quickly, and defensive stops need to happen very quickly to prevent harm
to yourself or your loved ones. So, while you might get a psychological
stop out of the small calibers, and they might even be plenty lethal,
they may not be enough to force a stop in a dedicated opponent. But what
about the other calibers? Certainly a 38SPL and a .44Mag are vastly
different when it comes to fight-stopping effectiveness, right? Not
really.
But don’t take my word for it, read this article by Greg Ellifritz:
An Alternate Look At Handgun Stopping Power
Look at the data. It’s pretty clear, I think. We’re talking about
minor differences between these rounds, overall. These are differences
in degree, not in kind. Even comparing the .22 to the .44 magnum we
don’t see astounding differences. Basically, everything is within about
20% of each other at the very most. We’re not seeing a steady,
consistent rise in effectiveness as we go from smaller, weaker rounds to
larger, more powerful rounds. What that says to me is that people don’t
like being shot. Maybe they like being shot with big bullets a little
less than with little bullets? It’s a bit moot, though, since the one
thing we can never know is how a given attacker would have responded to
another caliber. Proponents of the .45ACP will point to times when the
9mm has failed to stop an attack, and cite it as an example of how the
9mm isn’t an effective defensive round. Unfortunately for them, this
isn’t good science. We don’t know that the same person, in the same
situation, if shot in the same places with a .45ACP would have stopped
his attack. We
can’t know that, and that’s the only thing that
could definitively say whether one was “more effective” than another for
a given situation. Incidentally, we also don’t know if a person who was
effectively stopped with a .45ACP would have been similarly stopped
with 9mm rounds. It’s entirely possible that he would. There are too
many variables, and too little reliable data for anyone to ever truly
unravel all of it. That’s just reality, so we’re doomed to compare
apples to oranges forever.
Here’s what we can take from that data, though. Most attackers
required 2-4 shots to cease aggressive actions. The caliber matters less
than getting multiple good hits. Which rounds will allow you to get
multiple good hits? Generally those that produce less recoil. So you
need enough energy to provide for sufficient penetration to damage vital
organs (in case the psychological stop isn’t happening) but not so much
that you can’t get quick, accurate hits. As with so many things in
life, we’re seeking a balance. For me, the 9mm Luger provides the best
balance of capacity, penetration capability and rapid-fire accuracy.
Even with a compact 9mm, I can still carry 14 rounds, and I can get good
hits on target quickly. For me, that’s the right balance. I also carry
with 124-gr +P rounds, so I’m adding more weight (standard is 115-gr)
and more velocity to the standard 9mm loading.
Now, just to complicate matters, I want to bring your attention to a
another article. This is a direct response to the article linked above,
written by Grant Cunningham. I’ve linked to him many times before,
because I love his writing and his thinking. Here’s the article:
A Different Take on Handgun Stopping Power
He has some concerns with the statistical rigor of Ellifritz’s piece,
but still prefers it to some other famous discussions of the topic.
Cunningham’s conclusions are pretty similar to Ellifritz’s when all is
said and done, too. Most handgun rounds will do the job with 2-4 good
hits, and the bigger, beefier rounds are not necessarily the only way to
get an effective stop. Here’s Mr. Cunningham’s conclusion: “Bottom
line: pick your gun based on your ability to use it efficiently,
practice frequently and realistically with it, and you’ll be far more
prepared than the average gunshow denizen who loudly proclaims that all
good self defense calibers must begin with ‘.4′.” Here’s Mr. Ellifritz’
conclusion: “No matter which gun you choose, pick one that is reliable
and train with it until you can get fast accurate hits. Nothing beyond
that really matters!”
Seems pretty consistent. Train hard with whatever you intend to use for defense, because fast, accurate hits are what matter.
If you’re really interested in a much more in-depth examination of
everything that goes into stopping power, you should definitely read
Grant’s
Stopping Power Series.
He covers all of the things I’ve covered here and more, and has a much
greater depth and breadth of knowledge. So if you’ve got the time and
the inclination, I highly recommend reading through the whole series.
A couple things you might have heard that I hope we’ve debunked:
- “All good defensive calibers start with a 4.” – grant even mentions
this one in his conclusion, quoted above. It’s incredibly common in the
firearms world. The people saying this are claiming that .40 S&W is
the smallest caliber that will be an effective defensive round. Do the
data support this? Clearly not. This is, to be blunt, bullshit
posturing. It’s the sort of thing that people say when they haven’t done
any research on the topic, but when they want to sound very manly.
Apparently reading isn’t manly?
- “Carry the biggest caliber you can handle.” – This one is squirrely.
If by “handle” you mean delivering fast, accurate shots under stress
consistently, then this is at least sort of okay. The problem is that
you don’t have to carry the biggest round you can handle to be
effective. I can shoot a 10mm quite well (I even got some darned good
hits with a .500 S&W magnum the other day), but I carry a 9mm
because I shoot it faster and more accurately at speed. I bet I’m not
the only one who experiences an improvement in shooting performance by
stepping down from my maximum caliber, either. This is where that
balance comes in. Personally, I want to end any defensive encounter as
quickly as possible. If I can get 2-3 good hits with quality 9mm
defensive ammunition in under 3 seconds (and I can), that’s better to me
than getting those same hits in 4 seconds with a .45ACP (I also can).
In this case, the biggest caliber I can handle isn’t the best fit for my
goals as a defensive shooter.
I’ll leave you with my conclusion, which will echo those of the other
gentlemen: Your success in a defensive encounter is much more about
training, mindset, speed, shot placement and ammunition quality than it
is about caliber. Pick a gun you can control, practice with it a lot
(under stress when possible), and carry it loaded with quality
ammunition.
For more by the author visit
HERE
