Okay, folks. I wrote this a long time ago on an email list, and I'll repost it in part here.
Most of the following arguments are taken indirectly from sources like:
http://www.firearmstactical.com/marshall-sanow-discrepancies.htm
and
http://www.kuci.uci.edu/~dany/firearms/stoppers.html
and
http://www.recguns.com/Sources/OutIV.html
and
http://yarchive.net/gun/ammo/marshall_sanow.html
... in other words a few aricles found on the first page of Google if
you search for: Marshall Sanow
There are a few problems with their data beyond my own personal doubts.
How are One Shot Stops (OSS's) calculated?
1) Only torso shots were used;
2) Multiple hits were also discarded. "Again, I didn't consider it a
true indication of any round's performance to include instances where
the victim took three hollowpoints in the chest and collapsed. ... If I
included multiple hits this study could legitimately be attacked on the
grounds that multiple hits are not a reliable indicator as to any
round's stopping power.";
3) A stop was defined as: "if a victim was assualting someone, he
collapsed without being able to fire another shot or strike another
blow. If he was fleeing, he collapsed within 10 feet.";
4) "In order to include a shooting in this study, I insisted on either
having or being able to review some of the folowing: police reports,
evidence tech-nician reports, statements by the victim (if he survived),
homicide reports, autopsy results and photos. Whenever possible, I also
talked to the emergency room doctors and attending physicians";
5) Recovered bullets were either personally examined or photographed by
Marshall or photos were provided by a second party. He noted that there
were several stops where the hollowpoints failed to expand convincing
him that bullet placement is the real key to stopping power.
6) A minimum number of five shootings was required for the load to be
included in the study.
The problem lies with the second criterion. He discards all data where
more than one hit was recorded. But if it takes three shots, shouldn't
that technically count as a failure of the load to be a "One Shot
Stop"? Instead, they're ignored.
Next, try subtracting the data in Petersen's 1988 report from the 1992
"Handgun Stopping Power" and the 1992 HSP dataset from the "Street
Stoppers" 1996 data.
(
http://www.firearmstactical.com/tacticalbriefs/volume3/number1/TABLE2-1.PDF)
Since they are all ostensibly continuations of the same data set, this
procedure should give you three time periods, each distinctly reporting
the time period over which it was collected. With me so far?
Now, look at each data set.
Some cartridges in the second data set (supposedly collected between
1988 and 1996) come out with 100% or greater effectiveness rating. As
in, there were more "stops" attributed to a specific cartridge recorded
between those dates than there were shots fired using that same
cartridge.
An example of some possible discrepencies?
Let's look at the .380 ACP Federal 90- grain JHP. It scored 59% in the
1988 publication, 63% in the 1992 publication and 69% in the 1996
publication. Reasonable to assume that the ammunition is improving,
maybe? Work the numbers out and you find that between 1992 and 1996
this round jumped to 100% effectiveness. Hmmm ... well, sometimes
that's just the way the cookie crumbles, eh? I guess over the 4 years
between 1992 and 1996, the 15 shots that were counted here with the
Federal .380 JHP were all perfect OSSs. Could just be good luck, right?
How about the .45 ACP CCI 200-grain JHP?
In the 1988-1992 data set it scored 19 stops in 16 incidents.
That means that if you're carrying CCI 200-grain JHP in your pistol
you're more likely to stop a baddie by shooting him than you are to be
assaulted by one and end up shooting him.
There about 16 instances of this kind of glaring sample error.
Still seem sound? If there are errors that big, how accurate can the
rest be?
But for the sake of debate, let's just say that these were typos or
something else relatively dismissable (a typo that you may be staking
your life on, mind you).
Remember the criteria for a OSS? Remember the one about Marshall says
"I insisted on either having or being able to review some of the
folowing: police reports, evidence technician reports, statements by the
victim (if he survived), homicide reports, autopsy results and photos.
Whenever possible, I also talked to the emergency room doctors and
attending physicians";?
And remember the bit about
"Recovered bullets were either personally examined or photographed by
Marshall or photos were provided by a second party."
There were 20,742 cases listed in the 1996 "Street Stoppers" book. That
was an increase of 14,606 cases from the 1992 data. If we say he spent
no more than an average of two hours on every case (reviewing police
reports, evidence technician reports, statements by surviving victims,
homicide reports, autopsy results and photos and interviewing ER doctors
and attending physicians) and threw no cases out (i.e. assuming every
case that he found ended up fitting his criteria) than he spent 29,212
man-hours on this book (just updating it from 1992, remember).
A person who works 8 hours a day and takes no vacation beyond weekends
puts in about 2,088 hours each year. That means he either had 14 people
working full-time (no over-time, but no vacations either) on this
project for four years or he did nothing else for 20 hours each day,
every day. Even given so many benefits of the doubt (that he was able
to fully evaluate each case in two hours including processing all
evidence requests, photos, interviews and everything, that he only found
suitable cases, etc), there is simply too much data here for me to
believe he was able to process it.
I think I've said enough on this.