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I recently picked up a very informative book, titled "Modern Combat Ammunition" by Duncan Long, published by Paladin Press.
In it the author covers a large majority of commercially available & surplus ammunition for pistols, rifles, and shotguns. Several chapters are devoted to handloading & creating combat cartridges for pistols, rifles, and shotguns; and also covers exotic military and civilian rounds (exploding, AP, APIT, flechettes, riot, etc).

In the beginning of the book, he explains the RII ("Relative Incapacitation Index") of a given cartridge, which is based on the amount of disruption caused to ballistic gellatin. Also noted are several studies done by the FBI and other law-enforcement agencies.
The book then covers PIR ("Power Index Rating"), which the author considers as giving ratings close to real-world performance, without having to use ballistic gellatin. This equation can be found online as well, and the example given here is from the book.

PIR can be figured as such:

PIR = (V"squared" x E x B / 12111) x D
V= Velocity in Feet per Second
E= Energy Transfer
B= Bullet Weight in Grains
D= Diameter of Bullet

To find E; a bullet that expands has an "E" rating of 0.0100.
A nonexpanding bullet with a flat-nose that equals 60% of the bullet's diameter has a rating of 0.0085.
All other nonexpanding bullets have a rating of 0.0075.

To find D; this rating is based on the bullet's diameter given in inches.
.2 - .249 = 0.80
.25 - .299 = 0.85
.3 - .349 = 0.90
.35 - .399 = 1.0
.4 - .449 = 1.10
.45 - .499 = 1.15

Here's the example given in the book, using a .38 Special Federal Nyclad expanding hollowpoint:

Fired from a 6" barrel, it has a velocity of 915fps (V).
It's weight is 125 grains (B)
It will expand reliably; it's (E) rating is 0.010
The .38 Special (and .357 Magnum) uses bullets with a .357 inch diameter, so (D) is 1.0

Plug in the numbers-
PIR = (915x915 x 0.010 x 125 / 12,111) x 1.0
PIR = 86.41 (round off to the nearest whole) = 86

Here's the PIR Table
PIR 24 or less : Target shooting / plinking
PIR 25 - 54 : Small Animals / minimal self-defense
PIR 55 - 94 : Marginal Self-Defense
PIR 95 - 150 : Military or Self-Defense
PIR 151 - 200 : Self-Defense Only with enough practice to allow quick recovery from recoil.
PIR 201 or more : Hunting large animals only. Recoil and muzzle-blast make these rounds unsuitable for self-defense use.

"Modern Combat Ammunition" also gives a percentage of fights stopped with a single shot for several cartridges. These numbers are sourced by the author from firearms expert Evan Marshall, who kept records of success rates for given cartridges in stopping an opponent with a single shot.

For example:
The 9mm Parabellum with a Federal HP stopped fights with a single shot 72% of the time.
The .38 Special with a 158gr. LHP provided a one-shot stop rate of 64%.
The .357 Magnum with a 125gr. JHP provided a one-shot stop rate of 91%.
And the .45ACP rate 74% one-shot fight stoppers with 200gr. CCI JHPs.

For each cartridge, the author considers the effects of standard HP rounds fired through layers of denim / heavy clothing; the effects of rounds with cannelures; cartridge capabilities with +P or +P+ loads, frangible/exotic cartridges (Magsafe, Glaser), and many other variables.

Pistol cartridges detailed in this book are:
.22 Short, .22LR, .22 Short Magnum, .22 Win Magnum, .25Auto
7.62x25mm, 7.65 Luger, 9x18mm Makarov, 9x18mm Ultra/Police,
9mm Luger/Parabellum, 9mm Luger Rimmed, 9mm IMI, 9mm Major, 9mm Win Mag,
10mm Auto, 10mm Auto Mag,
.30 Carbine, .32Auto, .32S&W, .32S&W Long, .32H&R Mag, .380 Auto,
.354 S&W, .38S&W, .38 Special, .38 Super Auto, .357 Mag, .357 Maximum,
.40S&W, .41AE, .41 Avenger, .41 Mag, .44 Special, .44 Mag, .45 Colt, .45ACP,
.45 Hirtenberger Pistol, .455 Webley, .45 Win Mag, .451 Detonics Mag, and .50AE
 

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The book sounds interesting, but I'll immediately take issue with his contention that a 9mm round (even if HP) has a one round incapacitation rate of 72% while a .45 ACP is only 74%. Real world experience would give numbers more like 40% for 9mm and 90% for .45 (and I'm actually a .357 and .40 cal fan myself).
 

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The book sounds interesting, but I'll immediately take issue with his contention that a 9mm round (even if HP) has a one round incapacitation rate of 72% while a .45 ACP is only 74%. Real world experience would give numbers more like 40% for 9mm and 90% for .45 (and I'm actually a .357 and .40 cal fan myself).
Your evidence for this is...? The author appears to have done a good amount of research. I've yet to have someone show me how a well-placed 9 will not do the job when a well placed .45 will. The actual ability of the rounds to stop targets are very close.
 

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Your evidence for this is...? The author appears to have done a good amount of research. I've yet to have someone show me how a well-placed 9 will not do the job when a well placed .45 will. The actual ability of the rounds to stop targets are very close.

but EVERYONE knows that a 9mm is basically a .22, and has no stopping power, while the mighty .45 especially when fired out of a 1911, can kill someone with a shot to the pinky.
 

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but EVERYONE knows that a 9mm is basically a .22, and has no stopping power, while the mighty .45 especially when fired out of a 1911, can kill someone with a shot to the pinky.
What??? You mean there are .45's other than 1911's?!?!? ;)
 

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My evidence is 30 years of seeing, thru a career in law enforcement, what pistol rounds actually stop people and what don't. While the 9mm isn't a terrible round, it is simply mediocre. It compares rather favorably with a .38 special in the real world. Yes, a perfectly placed 9mm round will stop almost anyone, but how many perfectly placed rounds happen in the heat of combat? Very few. While I'm not one of .45 or die folks, it's hard to find a better man-stopper. I personally don't prefer them because that big slow round tends to not go thru cars very well, but for home defense they are outstanding. For perspective, sometime go to a range where they shoot at pepper popper steel plates and watch what happens with .45's, .357's, and then 9mm's. It sort of boom, boom, and then pop. When you carry a 9mm like I did for 8 years, it makes you start to check things out for yourself. What I found wasn't very impressive. There's a good reason why most law enforcement agencies have abandoned the 9mm.
 

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My evidence is 30 years of seeing, thru a career in law enforcement, what pistol rounds actually stop people and what don't. While the 9mm isn't a terrible round, it is simply mediocre. It compares rather favorably with a .38 special in the real world. Yes, a perfectly placed 9mm round will stop almost anyone, but how many perfectly placed rounds happen in the heat of combat? Very few. While I'm not one of .45 or die folks, it's hard to find a better man-stopper. I personally don't prefer them because that big slow round tends to not go thru cars very well, but for home defense they are outstanding. For perspective, sometime go to a range where they shoot at pepper popper steel plates and watch what happens with .45's, .357's, and then 9mm's. It sort of boom, boom, and then pop. When you carry a 9mm like I did for 8 years, it makes you start to check things out for yourself. What I found wasn't very impressive. There's a good reason why most law enforcement agencies have abandoned the 9mm.
And a .45 will do very little if it doesn't make a good hit either. The data shows a .357 is a far better man-stopper than a .45. Police abandoned the 9mm due to the abysmal performance of the hollow points... and they're had plenty of issues with other calibers. Hollow points are much better now, and in the long run police may be going back to 9mm. I also do not think the sound of hitting a steel plate is the best way to judge a round. A proper 9mm is going to be a plenty effective manstopper... the problem is there are a lot of underpowered 9mm loads out there still.
 

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I happen to agree that the .357 magnum is the best all-around pistol round, but don't hold you're breath for police agencies to return to 9mm.
 

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very few police use the .45 now correct?

I thought they all were using either 9mm, 40, or .357 sig

did the book happen to give a one stop shot percentage for 7.62x25 and 9mm mak and can i ask what they were?
 

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Assuming that no one makes a practical .357 magnum autoloading pistol, the police departments will likely settle on .40S&W, .357 SIG or .45 GAP. 9mm is perceived as too little, .45 ACP and 10mm too much. .357 SIG and .40 S&W come close to .357 performance but don't quite make it. I wonder how a .45 necked down to 9mm would work (the 9x25 dillon, 10mm necked down to 9mm, apparently was unusable.) The .400 corbon seems to get good reviews.
 

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Discussion Starter #11
The author's information was indeed gained from real-world reports & studies; the FBI Law Enforcement Bulletin (& the FBI's rating system), a study done by R.C. Dobbyn, W.J. Bruchey, and L.B. Shubin for the Department of Justice ("An Evaluation of Police Handgun Ammunition"), firearms-expert Vincent DiMaio's "A Comparison of Wounding Effect of Commercially Available Ammunition Suitable for Police Use" (as an article in the FBI L.E. Bulletin), and many other sources.

These studies investigated by the author showed why the .45ACP is a marginal, yet adequate, combat cartridge; it does not provide reliable expansion.
The lack of expansion with .45 rounds is due to the relatively sedate velocities achieved by a nominal defensive hollowpoint cartridge. 800fps is the minimum velocity needed for reliable expansion (even above that, some rounds don't expand), and many commercial .45ACP rounds hover just above that limit. Using short-barrel compacts will further reduce the velocity, making it an almost certainty that a commercial JHP will fail to expand.
In an attempt to increase expansion, manufacturers started making +P .45 JHP cartridges. Unfortunately, this also increased recoil impulse and bore wear. Advances in JHP design have somewhat achieved what upping velocity was intended to do; but the .45ACP still does not exhibit the expansion that smaller, high velocity rounds provide. The debate that a large-mass, slow-moving round is made effective by dumping energy inside the target, has come under fire. Studies are showing that expansion & penetration are more effective at providing incapacitation.

The issue with 9mm JHPs that police had wasn't entirely due to poor expansion; it was largely because of overpenetration. The FBI dropped the 10mm for much the same reason.

Comrade Antibiotika said:
I wonder how a .45 necked down to 9mm would work (the 9x25 dillon, 10mm necked down to 9mm, apparently was unusable.)
One of the members over at Gunsnet has reamed a Norinco 213 9mm to accept the 9x23mm Winchester. This cartridge has nearly the same ballistics as the .357 Mag, yet exhibits less recoil. I'd say a pistol chambered for the 9x23 WinMag is a viable alternative to the .357; allowing for more capacity and easier follow-up shots.

Did the book happen to give a one stop shot percentage for 7.62x25 and 9mm mak and can i ask what they were?
No, the author did not give a rating for those two cartridges.
For the 7.62x25-
"The 7.63 Mauser didn't thrive in the West for the simple reason that it wasn't very good; only Communist bureaucracies saved the 7.62x25mm from the same fate. Don't use this cartridge unless it has an expanding HP bullet; something not readliy available in ammunition being manufactured in Eastern Europe & China because of restrictions imposed by the conventions of war."

The 9x18 Makarov-
"In terms of power, the Makarov cartridge falls between the .380 Automatic and the 9mm Luger. Coupled with the poorly designed non-expanding bullets that plague most of these cartridges, the 9x18 Makarov is a second choice to either the .380 Auto or the 9mm Luger."
 

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The author's information was indeed gained from real-world reports & studies; the FBI Law Enforcement Bulletin (& the FBI's rating system), a study done by R.C. Dobbyn, W.J. Bruchey, and L.B. Shubin for the Department of Justice ("An Evaluation of Police Handgun Ammunition"), firearms-expert Vincent DiMaio's "A Comparison of Wounding Effect of Commercially Available Ammunition Suitable for Police Use" (as an article in the FBI L.E. Bulletin), and many other sources.

These studies investigated by the author showed why the .45ACP is a marginal, yet adequate, combat cartridge; it does not provide reliable expansion.
The lack of expansion with .45 rounds is due to the relatively sedate velocities achieved by a nominal defensive hollowpoint cartridge. 800fps is the minimum velocity needed for reliable expansion (even above that, some rounds don't expand), and many commercial .45ACP rounds hover just above that limit. Using short-barrel compacts will further reduce the velocity, making it an almost certainty that a commercial JHP will fail to expand.
In an attempt to increase expansion, manufacturers started making +P .45 JHP cartridges. Unfortunately, this also increased recoil impulse and bore wear. Advances in JHP design have somewhat achieved what upping velocity was intended to do; but the .45ACP still does not exhibit the expansion that smaller, high velocity rounds provide. The debate that a large-mass, slow-moving round is made effective by dumping energy inside the target, has come under fire. Studies are showing that expansion & penetration are more effective at providing incapacitation.

The issue with 9mm JHPs that police had wasn't entirely due to poor expansion; it was largely because of overpenetration. The FBI dropped the 10mm for much the same reason.



One of the members over at Gunsnet has reamed a Norinco 213 9mm to accept the 9x23mm Winchester. This cartridge has nearly the same ballistics as the .357 Mag, yet exhibits less recoil. I'd say a pistol chambered for the 9x23 WinMag is a viable alternative to the .357; allowing for more capacity and easier follow-up shots.



No, the author did not give a rating for those two cartridges.
For the 7.62x25-
"The 7.63 Mauser didn't thrive in the West for the simple reason that it wasn't very good; only Communist bureaucracies saved the 7.62x25mm from the same fate. Don't use this cartridge unless it has an expanding HP bullet; something not readliy available in ammunition being manufactured in Eastern Europe & China because of restrictions imposed by the conventions of war."

The 9x18 Makarov-
"In terms of power, the Makarov cartridge falls between the .380 Automatic and the 9mm Luger. Coupled with the poorly designed non-expanding bullets that plague most of these cartridges, the 9x18 Makarov is a second choice to either the .380 Auto or the 9mm Luger."



The author has done a lot of good work, but he is behind the times on the last 2 cartridges as hollowpoints are now available for both. No reflection on the author as there is no way that a book published today will have next weeks new products, unless the author can foretell the future.....I believe that the 7.62x25 and related ( 7.63 and 7.65 Luger)
cartridges probably derive greater benefit from expanding bullets than most handgun rounds.
 

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paladin Press likes to publish books with outdated info in them. I bought a book like in 1998 I think about body armor. The copyright date was from 1986!
 

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The 9x18 Makarov-
"In terms of power, the Makarov cartridge falls between the .380 Automatic and the 9mm Luger. Coupled with the poorly designed non-expanding bullets that plague most of these cartridges, the 9x18 Makarov is a second choice to either the .380 Auto or the 9mm Luger."

I'd have to disagree with the author there. While 9x18 mak may not be better than 9mm, it is sure as hell better than .380. Hornady XTP hollowpoints are very well performing, and the 9x18 is hotter than the .380.
 

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Discussion Starter #16
General Julian Hatcher's mathematical formula for determining the relative stopping power of handgun cartridges.

Hatcher Table
 
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