How important is the Service Caliber you choose?

General Firearms Terminal Ballistic Information
1

I am in the process of reading the instructor Manual “Tactical Anatomy” by James Williams M.D.

In the manual a slide is shown showing the expansion by caliber. as seen below

.http://i459.photobucket.com/albums/qq319/DocGKR/Handgun_expanded_JHP.jpg

I believe Dr. Williams makes the following important point in the manual:

Comparing the 9mm bullet to the 45 ACP bullet, we see that the diameter of the 45 (0.74) is only 13% larger than the 9mm (0.62). The calculated internal surface area of the wound cavity made by the 9mm bullet is 25.1 square inches. The internal surface area of the wound created by the 45 ACP bullet is 29.9 square inches (only 8.4% larger than the 9mm)

In other words, the amount of bleeding created by the 9mm is very likely to be indistinguishable from the bleeding created by the 45 ACP, if both bullets expand as intended and if both bullets pass through similar tissues.

The caliber of the handgun carried by a peace officer or legally armed citizen provided it is kept within the range of modern police ammunition choices, 38 Special +P and larger is less important in terms of wounding capacity than is choosing a caliber and handgun that allows the LEO to place his shots reliably and accurately.
END OF QUOTE

This quote makes a lot of since to me, and is why I like the 9mm and the Glock 19!

2

The primary reason for the FBI going from the 9mm to the .40S&W was due to the poor penetration ability of the 9mm. Police officers are often involved in gun battles. In gun battles, the participants often use cover and concealment. In civilian gun fire exchanges…not so much.

The 9mm does a little better now days with bonded bullet technology. The .40 is still a more reliable penetrator, and in a police setting I still prefer to use .40 for that application. With more advanced .40 pistols like the M&P, the .40 really shines. It is much more controllable, more durable, and has almost the same capacity as a 9mm.

That being said, I still think that the 9mm is an excellent civilian cartridge. With ammunition shortages, I think that everyone should have at least two handgun calibers…9mm and .40S&W. If you can’t find good 9mm ammo, you can always find good .40S&W ammo given the popularity with LEOs.

3

On a scale including mindset, situational awareness, marksmanship, training, command presence, tactics and luck, caliber choice is the bottom rung.

4

The frontal area varies with the square power of the diameter… so a 0.74" diameter bullet has 42% more frontal area than a 0.62" bullet.

Given that both should penetrate similarly (perhaps the 45 a little better), I find it difficult to believe that the internal surface area of the wound created by the 45 ACP bullet is only 8.4% larger than the 9 mm.

5

Another way to look at it is through the overall wound volume that the expanded bullet makes. The average recovered diameter of the 9mm is .60", the .40 is .65", and the .45 is .70". Recovered diameter is defined here:
https://www.m4carbine.net/showthread.php?t=26028

Lets say that you shoot someone with a perfect frontal shot and their torso is 10" from front to back. Here’s how much tissue and bone is taken out if the bullet exits the body:

9mm = 2.8 cubic inches
.40S&W = 3.3 cubic inches
.45acp = 3.8 cubic inches

Now what does that mean exactly? When it comes to physical hole size, the .40 is 15% more damaging than the 9mm, and the .45 is 26% more damaging than the 9mm. Now that doesn’t account for the improvements in external barrier penetration, nor the improvements in internal bone damaging with the larger calibers.

Based on hole size alone, the .40 is a bigger improvement over the 9mm, than the .45 is over the .40.

So there is definately something to be said for using the larger caliber. Bigger hole size(faster bleed-out/more likely to hit important stuff), better exterior barrier penetration, better interior barrier penetration(bone), better momentum(easier to bounce rounds off pavement),…etc.

The caliber we choose is often based on what each of use considers to be the ideal compromise between factors such as pistol size/weight, ammo costs, magazine capacity, and shootability. With new and better .40s and .45s on the market now days, it’s becoming easier to shift our ideal balance in favor of the larger calibers. I still find my balance point to be with the .40, and I probably won’t go any bigger. If I have my first choice in ammunition, I’ll go with the 9mm as well.

Find your happy place :smiley:

6

Did you like this Manual?

7

Thanks for the post, but I will have to respectfully disagree, unless the testing by Winchester and Speer are flawed. As you can see the penetration and expansion of the 9mm and 40S&W are very close. Here are the results of their published testing

9mm Gold Dot 124 +P
Bare Gel: 11.78"/.720"
Heavy cloth: 14.13"/.600"
Steel : 27.63"/.460"
Wallboard: 12.52"/.660"
Plywood: 14.00"/.594"
Auto Glass: 14.95"/.543"
Denim: 15.88"/.560"

40S&W Gold Dot 180 gr.
Bare Gel: 12.19"/.640"
Heavy cloth: 13.25"/,709"
Steel: 19.60"/.507"
Wallboard: 12.75"/,673"
Plywood : 17.10"/.575"
Auto Glass: 12.75"/.612"
Denim: 14.10"/.662"

9mm Winchester RA9T 147 gr.
Bare Gel:13,9"/.65"
Denim: 14.5"/.66"
Heavy cloth: 14"/.66"
Wallboard: 15"/.67
Plywood: 14.8"/.62
Steel: 17"/.45"
Auto glass: 10,8"/.52"

40 S&W Winchester RA40T 180gr.
Bare Gel: 13.8"/.60"
Denim: 14.3"/.70"
Heavy Cloth: 13.4"/.64"
Wallboard: 13.1"/,66"
Plywood: 15.1"/.64"
Steel: 17"/.52"
Auto glass: 12"/.61"

8

Yes I like the manual, it is very informative.

9

Winchester does not do a 5-shot average, nor do they use proper measurement of the expansion which is “recovered diameter”. Taking the maximum expanded diameter point is unrealistic as in most shootings as the petals fold back and hug the truck resulting in smaller recovered diameter after passing through bone and cartilage. Almost ALL 9mm JHPs that have expanded in real world shootings end up with a recovered diameter of about .60". In .40 it is usually .65".

In any gel test, sometimes you get exceptional results, and not so good results from shot to shot. This is why you do a sample of shots and take the average. The FBI and IWBA have always done 5-shot averages to get a more accurate reflection of of each test samples to get more accurate results. The .40 always does better than the 9mm in average samples in both expansion and penetration. Most online testers do not use a 5-shot average because it is expensive and time consuming to do so. This Winchester data that you have referenced has been on the internet for almost 10yrs and the product line has changed several times since then.

ATK is not a valid tester either. They do not measure by RD, nor do they take adequate samples and estimate an average. They do not document their calibration results of their gel via shot BB either, and if they threw out blocks that did not meet calibration standards.

The best ammo tester right now is Dr. Gary Roberts. He follows the FBI protocols and if you do some searching you can find a lot of work of his in these forums. In fact, this forum was established basically for him after he moved all of his work from Tactical Forums. Dr. Roberts has also said that if he were to be a patrol officer again, his pistol of choice would be a S&W M&P in .40S&W. I think that indicates that he sees a viable improvement in terminal effects and/or barrier penetration from the 9mm to the .40S&W provided that the operator shoots it well. That being said, I do like the 9mm in many circumstances.

More info on Winchester:

[i]“…our online testing comparison tool uses the testing data that we aquired during early production runs of each lot and type. The Ranger T-Series used in the comparison tool was originally tested in 2001 with one shot per ballistic gel block. We did not conduct multiple shot tests as we did not feel that it was necessary. The same test proceedures were used for our Ranger Bonded-Series.”

Matthew Schroeder
Winchester Law Enforcement
Government Contact[/i]

10

sgalbra76,

please allow me a small correction,

if the 9 mm expands to 0.60", the 40 to 0.65", and the 45 to 0.70", then with any penetration depth (to simplify, all bullets considered fully expanded from entrance to exit/stop):

the 40 creates a 17% larger crush volume than the 9 mm

the 45 creates a 16% larger crush volume than the 40, and 36% more than the 9 mm

11

Thanks, I was never that good at math :smiley:

12

the 40 creates a 17% larger crush volume than the 9 mm

the 45 creates a 16% larger crush volume than the 40, and 36% more than the 9 mm

All well and good but those percentages don’t correspond to the actual difference in effectiveness between those calibers.

So far, no one has been able to scientifically measure those differences. They are probably very small and we will never know for sure.

13

You can talk about wound channel and expansion all you want but it doesn’t change the basic facts.

If you are waiting for the perpetrator to bleed out you better shoot him several more time, because it can take awhile.

Shoot placement and striking vital organs is the key to stopping somebody. Even a heart shot can give an attacker up to 30 seconds more to kill you just from the oxygen level left in his brain.

Penetration is more important than expansion. A big short hole does little to stop someone. A deep hole to vital organs is what it takes. The difference in hole size will have very little to do with it.

In recent shooting report where a bystander was shoot, the lady who had an ample layer of fat, only felt a sting on her side. The bullet barely made it past the fat and did not hit anything of importance. She was treated and released from the hospital. The wound channel made no difference and very rarely does.

Placement and penetration kills so a 9mm+P FMJ may well be a better choice than a .40 self defense round because of penetration.

14

147 grain 9mm rounds penetrate comparably to 180 grain 40 rounds and 230 grain 45 acp rounds. The 9mm’s poor reputation in the past for penetration was due to lighter bullets with lower sectional density.
Pat

15

I guess you are saying the ATK and Winchester data is flawed, outdated, and should not be used. I would just like to bring to your attention that Dr. Roberts has recently posted the same Winchester data when he was comparing calibers.

16

In regard to Winchester…Schroeder said it for himself. The RT design alone has changed several times since 2001.

Tell you what. Get yourself a copy of “Bullet Penetration” by Duncan MacPherson. Read it and then tell me what you think of ATK’s testings.

17

I was referring to barrier penetration. The 9mm is always at least a couple of inches shy of meeting the minimum in the windshiled test with regular JHP. The FBI was not satisfied with the penetration ability of the .35 caliber which is a major reason why they made the switch to the .40 caliber.

[i]The 9mm is no more effective than the .38 Special, which should not be surprising since they are the same caliber bullets (.35 caliber) at the same range of veloctities and bullet weights. The .38 Special has served us for a long time. It has severe limitations, which we are not willing to accept. It is woefully inadequate for shooting at people in cars, for example, and over half of our shootings involve vehicles. It is a marginally adequate wounding agent. We have had a number of 9mm shootings over the past couple of years, and if you define a good shooting as one in which the subject stops whatever he was doing when he gets shot, we have yet to have a good one and we are hitting our adversaries multiple times.

-Urey Patrick Special Agent FBI: Taken from 10mm Notes Briefing[/i]

So, you can see why the FBI decided to make the switch. Keep in mind that the FBI had used much heavier bullets in the .38spl for decades in full length revolvers and even with that high sectional density they were not happy. That’s not to say that the 9mm has not improved over the years, but this was the reason for the FBI ditching the 9mm.

Here’s some other good info from the same briefing:

[i]1. Initial Test Results (12/88-1/89) on which the decision was based:
A. .38 Special +P - 158gr lead hollow point
-Success rate meeting 12" minimum: 67.5%
-Wound volume(cubic inches): 2.16
-Average penetration: 11.76

B. 9mm Subsonic - 147gr jacketed hollow point
-Success rate meeting 12" minimum: 67.5%
-Wound volume(cubic inches): 2.82
-Average penetration: 13.84

C. .45ACP - 185gr jacketed hollow point
-Success rate meeting 12" minimum: 92.5%
-Wound volume(cubic inches): 3.98
-Average penetration: 19.95

D. 10mm FBI Load - 180gr jacketed hollow point(980fps FBI lite)
-Success rate meeting 12" minimum: 97.5%
-Wound volume(cubic inches): 4.11
-Average penetration: 17.9[/i]

Notice that the FBI load for the 10mm is the reduced power loading which is virtually the same as the 180gr .40S&W. The success rate calculation accounts for all FBI protocol barriers, not just bare gel. This is how the FBI continues to determine what caliber and loading that they use. Although, I think they have updated the testing criterias since then. In addition to the .40S&W, the FBI also uses the 9mm in limited roles such as in the MP-5. For that, they adopted the Winchester Ranger Bonded 147gr. Ammunition has improved over the years, but performance as a whole improves as you increase caliber size. Given equally well designed JHPs, the .40S&W will always do better than the 9mm. If it doesn’t, it is due to the particular bullet construction flaws of the manufacturer not the caliber itself.

18

SGalbra thanks for all of your explanations.

The data you cited above is the old FBI test results. Is there a new updated sheet that shows their testing data for all of the newer rounds out there (Ranger T, Gold Dot, HST, Win Bonded, etc.?)

19

Nothing available on the internet as far as I know. Most of this old FBI data was made available to the IWBA(no longer together), and the IWBA released it in their publications so that other law enforcement agencies could benefit from it. Most govt agencies like the FBI don’t make their research available to the public. You usually have to be part of another agency(fed, state, or local), and you request the information based on interagency training or research which is considered to be sensitive information. It is surprising that this original research even got out. The FBI might have thought that it was too valuable to not leak it out to other agencies around the country.

With the IWBA no longer around, much of the valuable knowledge learned from their govt studies isn’t getting leaked out to non Federal LEOs or the public.

At this time, the FBI has contracted Winchester for Ranger Bonded loads in .40 180gr, and 9mm 147gr. The .40 is used in pistols and some SMGs for the FBI, and the 9mm is mostly used in SMGs. That’s what they feel meets “their” needs.

If there is any doubts in your mind on what you should be carrying, I think it is a pretty wise decision to copy agencies like the FBI. More and more Federal agencies are going this route after years of trying to whistle their own tune. For example, Border Patrol had used the 135gr and 155gr .40 for many years. It turned out that most of the field officers and trainers were not happy at all with this load, but supervisors who had been in charge of RM(reference manual) requirements resisted changing to FBI standards. Many BP officers put in 30yrs, so these supervisors were around pre Miami shootout and were brought up on “stopping power” philosophy. In December of 2009, Border Patrol switched to the 180gr .40. I went to a LE refresher in January with 5 BP trainers and they very happy with the transition citing several OISs in which they were very unhappy with the penetration characteristics of the ligher .40 bullet weights.

All that being said, I am not a big fan of the FBI’s adoption of the Glock .40. It does okay if you keep a tight maintenance schedule, but it isn’t very forgiving if you don’t. I’ve heard FBI agents are required to keep a round count log on their pistols and keep their armorer up to date on that log. Also, I think that the 124gr+P bonded loading is better than the 147gr bonded in pistols. Keep in mind, the FBI mostly uses the 9mm 147gr bonded in SMG roles and the extra barrel length of the SMG might make it look a little better in FBI protocol testing.

20

This is one of my daily conundrums, unfortunately. I get a LOT of questions from other agents about “what gun should I buy” (we authorized any 9mm or .40 S&W semi-auto from 13 different manufacturers for personal use on duty).

I believe that, if you’re assigned to an agency which allows you to pick your own ammunition as well as caliber, you really shouldn’t look any further than the 9mm. I find that, platform to platform, the 9mm’s shootability, accuracy, and increased capacity FAR outweigh any potential improvement in terminal performance in “better” calibers.

If you’re like me, and restricted to carrying agency-issued ammunition and your agency issues REALLY BAD 9mm ammunition, then I’d advocate a different caliber IF YOU CAN HANDLE IT. What I mean is, if you can shoot a similar platform in .40 S&W with equal accuracy, and near equal speed, then I’d advocate the carry of the .40. In my case, while I REALLY dislike the .40 S&W for a variety of reasons, I shoot my G23 with more accuracy, and at a speed which is indistinguishably slower when compared to my G19 (five shots in .78 seconds with the G19; five shots in .82 seconds with the G23) - so I opt for the “more capable” caliber. I know LOTS of agents, though, who went .40 because it was “better” and now have pistols they don’t shoot well, and don’t like to practice with because of increased recoil (this is especially true of folks who’ve bought “subcompact” .40s like the G27 and Kahr PM40).

So, I usually end up writing long, twisted recommendations (like this one) - advocating specific calibers in specific platforms, and, usually, confusing people more than I help them!

Regards,

Kevin