Tuesday, September 30, 2003


5 November 2003

MILINET: The Stopping Power Myth

By: Mr. Bruce L. Jones

Inland Empire Mensa
copyright - 1994 & 1997

I am about to commit ballistic heresy. I suppose this admission
shouldn't be taken lightly, but feeling my steadily advancing years I am
too old to begin being a hypocrite at this stage of the game. I should
mention that some people I know consider me sane the majority of the
time, but the jury is still out.

I have been reading material written by very earnest people (grandaddy
was named Earnest) for at least thirty years arguing the relative merits
of one size pistol cartridge over another. The argument seems to center
around whether or not someone's favorite caliber will put an end to the
violent and sometimes maniacal attack of one of society's more
disenchanting creatures.

The theory de jure in today's glossier periodicals was developed by a
very sincere man named Evan Marshall who possibly has a pathological
need to help old ladies cross the street. I am not sure where he
acquired this pathogen but keep a firm grip on granny. Because of this
tendency, I feel certain that Mr. Marshall is one sterling fellow. I
would probably feel proud to call him a friend. Also, to his credit, he
comes very close to disavowing any belief in his own theory, stating in
his first book (which he would be happy to sell you) that the most
important component of stopping power is shot placement; but we'll get
to that later.

In his second book, Mr. Marshall - I am told - elaborates on the first
book to a large degree. I have yet to read it. I read the first through
an inter-library loan. The charge for an ILL then was only a quarter. In
their constant search to provide better service, my library has since
hiked the price for an ILL to three bucks. When my curiosity to read
book two of the same stuff contained in book one reaches a three buck
threshold, I'll get it on ILL, too. Until then I am blissfully content
to remain ignorant of the majority of it's contents.

Later on, we will get to a phenomenon of ballistics that no one else
considers; else referring to me. If you are a bright and inquisitive
kind of person, you will then want to find ways to run out and test the
information for yourself. For those somewhat less inquisitive, I'll give
you a method to use that you can do "for free". We will also include
some science of the absurd.

Sabers drawn, we enter the fray. There are two problems I have with
Marshall's basics. 1) His theory. 2) His data. Having said that, let us

Mr. Marshall arbitrarily chose to include data in his findings from
incidents wherein there was only a single fired round solidly striking
the torso. What? How's that? Gee, this - of course - leaves out all
other data. The problem here is that this excludes the majority of the
available information. The kind of data missed in this method is - e.g.
- the first shot fired, the second and subsequent shots fired, if any;
and the reasons for multiple shots being fired. I am not sure if there
are more tidbits being left out, but it seemed to me the first two
considerations should be: "how many shots were fired" and "why were they
fired". The total effect of all of this missing data is not fully

Now, it may be considered academic to exclude first shot misses (I don't
think so) but multiple pops should definitely be counted because the
first shot failed to accomplish the goal, as we will demonstrate. This
omission tends to make some products look better than they actually are.
In some circles this could be said to be deliberately misleading.
Everyone who wishes to be misled about the efficiency of their last
resort personal life saving device, raise your hand. What, none? I
didn't think so.

To take a close look at what I am talking about, lets look at some
make-believe data and some easy to crunch numbers. Lets say that data
collected for the .32 caliber had shown, under Marshall's method, 200
incidents where someone was solidly hit in the torso. Of those, 100 of
the people were hit only once. These were counted, the remainder
excluded (left 100 running amuck, I suppose). Thus, 100 single hits of
200 opportunities occurred and in 50 of those single shots the bad guy
surrendered. This equates to a 50 percent probability of a one-shot
stop. "Probability" is a word I am not crazy about were my life to be at
stake, but we'll get to that later, too.

Well, let's say that the 100 incidents were excluded from the data above
because they were multiple hits to the torso. Let's say, further, that
of those, 75 of the follow-up shots were fired because the first one
didn't phase the attacker (the other twenty-five were just double-tap
advocates). I call this a "failure to stop". This data should be
included. Why, you might ask (if you don't ask the article kinda stops

Well, if this data is included with the rest then the actual stops are
really 50 out of 175, not 50 of 100. This lowers the "probability" a
considerable degree; to less than 29 percent. By following his method,
Mr. Marshall inadvertently made poor performance appear much better. If
one did not know better, one might wonder if Mr. Marshall owned stock in
Seecamp. If he ever reads this I hope he knows I'm just kidding.

Of course, the better a cartridge performed, the less this particular
phenomena affected their respective data. But, the data are still
skewed. The best calibers still come out on top as the best performers,
but where is the "real data" in the noise? The problem with this last
statement is: it is true. The effect, however, is that it still leaves
in question just where this phantom line of separation lies between the
poor performers who have been accidentally made to look good and the
truly good performers that would actually enhance the probability of a stop.

For a minute, let's stop and consider the term "probability of a stop"
as used in Marshall's context. Few people understand "probability" in
it's actual sense. A reasonable person would look at the above data and,
if he carried a .32, would say, "Well, if the stop probability is 50%,
I'll just shoot him twice and it will be 100%." Wrong. That's "real
world math" not "math-math". With the rules for probabilities
(math-math) you can never get to 100 percent. Huh? What was that? I'll

If the .32 shows a 50 percent probability of a one-shot stop (sure it
does), then the first shot should stop half of the bad guys, half of the
time. The second shot should stop half of the rest of those that didn't
fall the first time; this makes only 75 percent! The third shot should
stop 50 percent of whoever's still standing hefting the total up to
grand 87.5 percent. And so-on and so-on. Using this method, we need
about four rounds from the .32 right off the top to approach what
Marshall states is the probability for a single round from a .357
magnum. Thus, reality is much more dismal that the bare numbers make it
seem. This becomes immediately worse if one starts with the more abysmal
29 percent rating developed from the multiple hit data.

Now for some fun.

All of this notwithstanding I have another major problem when
considering the data from Marshall's book. Put in the simplest terms,
the data base has no way of correlating the extent - or even if - the
skill of the individual shooter plays in the equation. Considering that
shot placement is the single most important factor in accomplishing a
ballistically inspired stop, the relative skill of the shooters must be
considered if one uses actual "street" data. If you do not, it would
tend to invalidate all of the data. I'll show how.

An example of what I am talking about can be demonstrated with some more
fictional data.

Lets suppose that we create two teams of shooters that will be exposed
to the need for expressing lethal force with a handgun.

The first team, let's call them Team 1, is comprised of 5 ft. tall, 100
lb., 80 year old great-grandpa's with no firearms training other than
basic instruction in how to fire the weapon. We assume that they can see
well enough to acquire the rear sight and have enough physical strength
to eventually pull the trigger with one or more fingers. We are not
entirely sure, they have never fired the weapon. They are armed with the
new H&K Mk. 23 Mod. 0 .45ACP SOCOM semi-automatic pistols loaded with
hardball ammo and carried in their bathrobe pockets. They carry Bugs
Bunny flashlights that their great-grand-kids left during their last
visit. To turn them on (no, the flashlights!), you have to push the
switch forward and bang the side of the lens bezel simultaneously.

The second team, let's call them Team 2, is made up of tall, well
muscled, young female clones of Gina Davis' character in "The Long Kiss
Goodnight". You know, your basic spy/ para-military types with 20-20
vision, each of whom can bench-press a Buick and are completely
impervious to pain. They are all highly practiced and trained;
experienced veteran combat shooters. They are armed with .22LR S&W Model
63 revolvers with the standard 4 -inch barrels and Aim Point Red Dots.
These are loaded with Stinger hollowpoints and carried in tactical
holsters strapped over skin-tight stretch-pants. They shun upper-body
tactical armor with hard panel inserts in favor of Versace t-shirts and
helmets with night and thermal sights built-in.

Now we send both teams onto the street in any of America's more blighted
urban centers on a typical weekend with instructions to secure their
respective areas. Naturally, they both have an unlimited supply of
ammunition and batteries.

Team 1 is involved in 40 incidents. They were able to actually discharge
their weapons in 27 of them. A remarkable 22 actually hit their targets.
Of these, 20 were torso hits; primarily love-handle perforations. They
experienced a total of 5 one-shot stops, all fired in their team's
classic stance; eyes closed with the weak side index finger in the
weak-side ear and the index and middle finger of the strong hand on the
trigger. Range averaged about 40 yards. A total of 27 rounds of
ammunition was expended.

Team 2, on the other hand, also had 40 incidents - in the first hour.
Each was a one- shot stop to the brain-case of the perpetrators. In each
instance the range was approximately 2 yards and firing was from the
isosceles stance. Having frightened off all other inhabitants in their
area they spent the remainder of the weekend target practicing on urban
self-propelled high-mobility targets (rats, dogs and cats). Team 2
expended a total of 3000 rounds of ammunition.

By the above example we can see that what everyone already knows is
proven beyond a doubt. The lowly .45 ACP is only a 25 percent one-shot
stopper and the amazingly effective .22 LR is a 100 percent one-shot

Now, I don't know about you, but if Team 2 does that good with .22
caliber revolvers, then I'm gonna run right out and buy a Ruger auto
pistol with a politically correct 10 round capacity so that I can be
perfectly protected against at least 10 bad-guys, right? And the H&K,
forget that. Who would want such an abysmal performer?

The examples provided by the experiences of teams one and two serve to
illustrate the importance of the skill, training and physical
capabilities of the shooter in the stopping power debate. These are
perhaps the most important factors of all.

At this point I ask myself, "Is there anything left out". Well, some
other fine folks like to ponder the effects of mass versus energy. I
think the eventual outcome is probably similar to the stopping power
index Marshall developed. I do know that one factor is observed and
seldom measured. For lack of a better term, I like to think of it as a
"radial pressure wave". This radial pressure wave is a very real
phenomenon that is characterized by a "wave" or cyclic series of
pressure that is radially dispersed from the point of ballistic impact,
perpendicular to the path of projectile trajectory. I first thought of
it hunting feral hogs.

I happened upon a particularly corpulent porker one day and placed a
solid hit with a large magnum caliber projectile just behind his front
shoulder. I also noticed that, almost immediately, a cloud of dust flew
off his back, as if he had given a mighty shudder. I don't think he
shuddered though as he just looked at me through his one-side eye as if
to say, "Huh?". He was unimpressed. He turned to look at me, then fell
over dead. I wondered about the dust cloud though, and sort of mentally
filed it away. Some years later, it would resurface in an unexpected way.

Fast forward to the Viet Nam war. Near the end of the war ( having
served my time) I was working - at the time - in an Army Depot helping
to assess battle damage of equipment that returned from the zone. There
I stood one fine afternoon surveying the side of a shelter (for
non-military types this is a camper-like box used in military trucks to
house all manner of portable facilities). There was a large impact hole
through-and-through the side. I was observing the entry side. The hole
was probably the result of a dud artillery shell that passed through
without exploding. It was large enough to stick my hand through,
probably made by about a 75mm. What caught my attention was the damage
caused by the impact. There was, for sure, the hole. But what was
different was that the entire aluminum skin was rippled and many of the
rivets that held it to the frame around the edges were popped loose. I
immediately thought the damage caused by some time of ripple effect
radiating from the center of impact.

When the skin was finally peeled back from the side of the shelter, some
of the interior ribs also had partial ripples and buckles radiating
outward from the center of impact. The damage was much more than what
would have been expected from just the material being displaced from the
path of the projectile. I began to ponder other examples I had seen of
this and I remembered my hog years before. Now I see the effects of this
pressure wave in almost every ballistic impact I examine (some materials
are so resilient it isn't observed). It is also three dimensional. It
travels forward along with the projectile. It is coincident with the
sound wave, but is more. The addenda is that pressure is increased
proportionately to the velocity and mass of the projectile. The
frequency of the pressure wave also fluctuates with changes in velocity
and mass. The frequency of the pressure wave is also altered by the
specific gravity of the object being struck. Material of differing
densities resonate at differing frequencies in response to the pressure

All of the ballistic test media used by modern researchers shows the
effects of this pressure. Water, wet newsprint, phone books, sacks of
flour, melons and the standby ballistic gelatin all reveal it. The
observable after-effect is now called the "crush cavity", either
temporary or permanent. The crush-cavity is only the after effect.
Radial Pressure Wave is the cause. It doesn't take a rocket scientist to
figure it out. If one looks at the crush cavity in ballistic gelatin
what you are observing is the physical evidence left behind by the
pressure wave traveling through the material.

If you want to ponder the effect and waste a little time here's what you do:

Gather up two sacks of pebbles. One sack should contain pebbles of
approximately a quarter inch in diameter. The other sack should contain
pebbles of about three-quarters of an inch in diameter. Don't be too
picky, size doesn't matter all that much. Retire to your favorite
swimming hole with appropriate refreshments and make yourself
comfortable. Drop one small pebble into the test media (the water) and
observe the ripples that evenly radiate outward from the center of
impact of your projectile (the pebble). This is the pressure wave.

Now repeat this procedure with one large pebble. Notice that the
resultant wave has a different appearance, or "signature" than the waves
created by the first pebble. Repeat this procedure, alternating between
large and small pebbles. Observe that with the different size pebbles
the height and distance between the little waves that they cause is
different with each, yet consistent among like-size pebbles. This is the
observable frequency of the pressure wave.

Now vary the experiment. Launch more pebbles downward, still alternating
size, but increase the introductory velocity by increasing the launch
momentum (throw them harder). As you do so, you will notice that the
frequency signature of the pressure waves change in a dramatic and
noticeable manner. They become higher and closer together. The pressure
waves also move through the test media with a noticeably greater
velocity between frequency spikes.

If you have chosen your refreshments carefully, after a while you will
be able to accurately predict the effect of the introduced projectiles
on the test media and the frequency of the pressure wave that will
result by varying the size of the projectile and the launch velocity.

Now, most people would be satisfied at this point. But, if you want to
pretend to be a scientist you can conjure up ways to test this
phenomenon even further. First, begin by varying the specific gravity of
the test media. Gradually increase the density. When the media becomes
dense enough to stand without support, stand it on it's side and place
pressure sensors all around it and feed the data they obtain into a
computer. The main problem with this is that the media will eventually
become too dense for you to penetrate by just throwing the pebbles by
hand. You may want to devise some kind of pyrotechnic-like method for
launching the pebbles so that they will penetrate the test media. In
fact, you may eventually want to switch from pebbles to something else.
Perhaps small, metallic pellet-like objects.

What might be gained from this? Well, if enough experimenting is done,
you may eventually discover that an optimal destructive pressure wave
exists for any given test media that induces some kind of sympathetic
resonance with only a certain mass and velocity of projectile. Or not. I
might conduct the research myself someday if I can find a benefactor to
fund it. Imagine, I could discover the perfect mass and velocity of
projectile that would create a pressure wave that would be 100%
effective in stopping an attacker. Or, I could find a hand gun I can
shoot well and practice, practice, practice.


This is...
Gunny G's...
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By R.W. "Dick" Gaines
GySgt USMC (Ret.)