Very interesting article posted over at loadoutroom.com on the adoption of 9mm by the FBI.
The FBI is Going 9mm: Here Comes the Science

UPDATE:
There have been some questions about the origin of this FBI statement.
As the word of the FBI’s solicitation for 9mm handguns became public,
they were hit with a flood of questions from state and local agencies,
many who carry .40, about the change. This statement was prepared the
FBI Training Division to answer those questions and was intended for
dissemination to law enforcement agencies. It was not classified Law
Enforcement Sensitive and has spread to civilians. I have confirmed its
origin and feel that its release poses no threat to law enforcement
while providing enlightening science, paid for by taxpayer dollars, to
the public.
After the Miami Shootout in 1986, the FBI invented modern ammunition testing and led the law-enforcement movement to
.40 caliber. The FBI is very conservative, and has one of the best ballistics labs in the world.
With
the amazing 21st-century advances in ammunition technology, many people
have advocated a move back to 9mm. Recently, the FBI announced they
were buying a new gun in 9mm. When the FBI makes a move like that, they
have thought it through very thoroughly.
I respect the science and
how hard it was for them to make this change. The FBI takes their
leadership role in law enforcement very seriously. Below is their
carefully crafted message, sent to other agencies, explaining their
reasons.
FBI 9MM Justification
FBI Training Division: FBI Academy, Quantico, VA
Executive Summary of Justification for Law Enforcement Partners
· Caliber debates have existed in law enforcement for decades
· Most of what is “common knowledge” with ammunition and its effects on the human target are rooted in myth and folklore
·
Projectiles are what ultimately wound our adversaries and the
projectile needs to be the basis for the discussion on what “caliber” is
best
· In all the major law enforcement calibers there exist
projectiles which have a high likelihood of failing LEO’s in a shooting
incident and there are projectiles which have a high ting incident
likelihood of succeeding for LEOs in a shooting incident
· Handgun stopping power is simply a myth
·
The single most important factor in effectively wounding a human target
is to have penetration to a scientifically valid depth (FBI uses 12” –
18”)
· LEOs miss between 70 – 80 percent of the shots fired during a shooting incident
·
Contemporary projectiles (since 2007) have dramatically increased the
terminal effectiveness of many premium line law enforcement projectiles
(emphasis on the 9mm Luger offerings)
· 9mm Luger now offers
select projectiles which are, under identical testing conditions, I
outperforming most of the premium line .40 S&W and .45 Auto
projectiles tested by the FBI
· 9mm Luger offers higher magazine
capacities, less recoil, lower cost (both in ammunition and wear on the
weapons) and higher functional reliability rates (in FBI weapons)
·
The majority of FBI shooters are both FASTER in shot strings fired and
more ACCURATE with shooting a 9mm Luger vs shooting a .40 S&W
(similar sized weapons)
· There is little to no noticeable
difference in the wound tracks between premium line law Auto enforcement
projectiles from 9mm Luger through the .45 Auto
· Given
contemporary bullet construction, LEO’s can field (with proper bullet
selection) 9mm Lugers with all of the terminal performance potential of
any other law enforcement pistol caliber with none of the disadvantages
present with the “larger” calibers
Justification for Law Enforcement Partners
Rarely
in law enforcement does a topic stir a more passionate debate than the
choice of handgun caliber made by a law enforcement organization. Many
voice their opinions by repeating the old adage “bigger is better” while
others have “heard of this one time” where a smaller caliber failed and
a larger caliber “would have performed much better.” Some even
subscribe to the belief that a caliber exists which will provide a “one
shot stop.” It has been stated, “Decisions on ammunition selection are
particularly difficult because many of the pertinent issues related to
handguns and ammunition are firmly rooted in myth and folklore.” This
still holds as true today as it did when originally stated 20 years ago.
Caliber,
when considered alone, brings about a unique set of factors to consider
such as magazine capacity for a given weapon size, ammunition
availability, felt recoil, weight and cost. What is rarely discussed,
but most relevant to the caliber debate is what projectile is being
considered for use and its terminal performance potential.
One
should never debate on a gun make or caliber alone. The projectile is
what wounds and ultimately this is where the debate/discussion should
focus. In each of the three most common law enforcement handgun calibers
(9mm Luger, .40 Smith & Wesson and .45 AUTO) there are projectiles
which have a high likelihood of failing law enforcement officers and in
each of these three calibers there are projectiles which have a high
likelihood of succeeding for law enforcement officers during a shooting
incident. The choice of a service projectile must undergo intense
scrutiny and scientific evaluation in order to select the best available
option.
Understanding Handgun Caliber Terminal Ballistic Realities
Many
so called “studies” have been performed and many analyses of
statistical data have been undertaken regarding this issue. Studies
simply involving shooting deaths are irrelevant since the goal of law
enforcement is to stop a threat during a deadly force encounter as
quickly as possible. Whether or not death occurs is of no consequence as
long as the threat of death or serious injury to law enforcement
personnel and innocent third parties is eliminated.
“The concept
of immediate incapacitation is the only goal of any law enforcement
shooting and is the underlying rationale for decisions regarding
weapons, ammunition, calibers and training.”1
Studies of “stopping
power” are irrelevant because no one has ever been able to define how
much power, force, or kinetic energy, in and of itself, is required to
effectively stop a violent and determined adversary quickly, and even
the largest of handgun calibers are not capable of delivering such
force. Handgun stopping power is simply a myth. Studies of so?called
“one shot stops” being used as a tool to define the effectiveness of one
handgun cartridge, as opposed to another, are irrelevant due to the
inability to account for psychological influences and due to the lack of
reporting specific shot placement.
In short, extensive studies
have been done over the years to “prove” a certain cartridge is better
than another by using grossly flawed methodology and or bias as a
precursor to manipulating statistics. In order to have a meaningful
understanding of handgun terminal ballistics, one must only deal with
facts that are not in dispute within the medical community, i.e. medical
realities, and those which are also generally accepted within law
enforcement, i.e. tactical realities.
Medical Realities
Shots
to the Central Nervous System (CNS) at the level of the cervical spine
(neck) or above, are the only means to reliably cause immediate
incapacitation. In this case, any of the calibers commonly used in law
enforcement, regardless of expansion, would suffice for obvious reasons.
Other than shots to the CNS, the most reliable means for affecting
rapid incapacitation is by placing shots to large vital organs thus
causing rapid blood loss. Simply stated, shot placement is the most
critical component to achieving either method of incapacitation.
Wounding
factors between rifle and handgun projectiles differ greatly due to the
dramatic differences in velocity, which will be discussed in more
detail herein. The wounding factors, in order of importance, are as
follows:
A. Penetration:
A projectile must penetrate deeply
enough into the body to reach the large vital organs, namely heart,
lungs, aorta, vena cava and to a lesser extent liver and spleen, in
order to cause rapid blood loss. It has long been established by expert
medical professionals, experienced in evaluating gunshot wounds, that
this equates to a range of penetration of 12?18 inches, depending on the
size of the individual and the angle of the bullet path (e.g., through
arm, shoulder, etc.). With modern properly designed, expanding handgun
bullets, this objective is realized, albeit more consistently with some
law enforcement projectiles than others. 1 Handgun Wounding Factors and
Effectiveness: Firearms Training Unit, Ballistic Research Facility,
1989.
B. Permanent Cavity:
The extent to which a projectile
expands determines the diameter of the permanent cavity which, simply
put, is that tissue which is in direct contact with the projectile and
is therefore destroyed. Coupled with the distance of the path of the
projectile (penetration), the total permanent cavity is realized. Due to
the elastic nature of most human tissue and the low velocity of handgun
projectiles relative to rifle projectiles, it has long been established
by medical professionals, experienced in evaluating gunshot wounds,
that the damage along a wound path visible at autopsy or during surgery
cannot be distinguished between the common handgun calibers used in law
enforcement. That is to say an operating room surgeon or Medical
Examiner cannot distinguish the difference between wounds caused by .35
to .45 caliber projectiles.
C. Temporary Cavity:
The
temporary cavity is caused by tissue being stretched away from the
permanent cavity. If the temporary cavity is produced rapidly enough in
elastic tissues, the tensile strength of the tissue can be exceeded
resulting in tearing of the tissue. This effect is seen with very high
velocity projectiles such as in rifle calibers, but is not seen with
handgun calibers. For the temporary cavity of most handgun projectiles
to have an effect on wounding, the velocity of the projectile needs to
exceed roughly 2,000 fps. At the lower velocities of handgun rounds, the
temporary cavity is not produced with sufficient velocity to have any
wounding effect; therefore any difference in temporary cavity noted
between handgun calibers is irrelevant. “In order to cause significant
injuries to a structure, a pistol bullet must strike that structure
directly.”2 2 DiMaio, V.J.M.: Gunshot Wounds, Elsevier Science
Publishing Company, New York, NY, 1987, page 42.
D. Fragmentation:
Fragmentation
can be defined as “projectile pieces or secondary fragments of bone
which are impelled outward from the permanent cavity and may sever
muscle tissues, blood vessels, etc., apart from the permanent cavity”3.
Fragmentation does not reliably occur in soft tissue handgun wounds due
to the low velocities of handgun bullets. When fragmentation does occur,
fragments are usually found within one centimeter (.39”) of the
permanent cavity.4 Due to the fact that most modern premium law
enforcement ammunition now commonly uses bonded projectiles (copper
jacket bonded to lead core), the likelihood of fragmentation is very
low. For these reasons, wounding effects secondary to any handgun
caliber bullet fragmentation are considered inconsequential. 3 Fackler,
M.L., Malinowski, J.A.: “The Wound Profile: A Visual Method for
Quantifying Gunshot Wound Components”, Journal of Trauma 25: 522?529,
1958. 4 Handgun Wounding Factors and Effectiveness: Firearms Training
Unit, Ballistic Research Facility, 1989.
Psychology
Any
discussion of stopping armed adversaries with a handgun has to include
the psychological state of the adversary. Psychological factors are
probably the most important relative to achieving rapid incapacitation
from a gunshot wound to the torso.5 First and foremost, the
psychological effects of being shot can never be counted on to stop an
individual from continuing conscious voluntary action. Those who do stop
commonly do so because they decide to, not because they have to.
The
effects of pain are often delayed due to survival patterns secondary to
“fight or flight” reactions within the body, drug/alcohol influences
and in the case of extreme anger or aggression, pain can simply be
ignored. Those subjects who decide to stop immediately after being shot
in the torso do so commonly because they know they have been shot and
are afraid of injury or death, regardless of caliber, velocity, or
bullet design. It should also be noted that psychological factors can be
a leading cause of incapacitation failures and as such, proper shot
placement, adequate penetration, and multiple shots on target cannot be
over emphasized. 5 Ibid.
Tactical Realities
Shot
placement is paramount and law enforcement officers on average strike
an adversary with only 20 – 30 percent of the shots fired during a
shooting incident. Given the reality that shot placement is paramount
(and difficult to achieve given the myriad of variables present in a
deadly force encounter) in obtaining effective incapacitation, the
caliber used must maximize the likelihood of hitting vital organs.
Typical law enforcement shootings result in only one or two solid torso
hits on the adversary. This requires that any projectile which strikes
the torso has as high a probability as possible of penetrating deeply
enough to disrupt a vital organ.
The Ballistic Research Facility
has conducted a test which compares similar sized Glock pistols in both
.40 S&W and 9mm calibers, to determine if more accurate and faster
hits are achievable with one versus the other. To date, the majority of
the study participants have shot more quickly and more accurately with
9mm caliber Glock pistols. The 9mm provides struggling shooters the best
chance of success while improving the speed and accuracy of the most
skilled shooters.
Conclusion
While some law
enforcement agencies have transitioned to larger calibers from the 9mm
Luger in recent years, they do so at the expense of reduced magazine
capacity, more felt recoil, and given adequate projectile selection, no
discernible increase in terminal performance.
Other law
enforcement organizations seem to be making the move back to 9mm Luger
taking advantage of the new technologies which are being applied to 9mm
Luger projectiles. These organizations are providing their armed
personnel the best chance of surviving a deadly force encounter since
they can expect faster and more accurate shot strings, higher magazine
capacities (similar sized weapons) and all of the terminal performance
which can be expected from any law enforcement caliber projectile.
Given
the above realities and the fact that numerous ammunition manufacturers
now make 9mm Luger service ammunition with outstanding premium line law
enforcement projectiles, the move to 9mm Luger can now be viewed as a
decided advantage for our armed law enforcement personnel.
This information was published by
Loose Rounds on September 21, 2014.