9mm/40/357SIG Penetration

[aterry33]

There is a lot of misinformation out there on the web, so I was curious about what everyone thought.

I have often heard it said that police agencies (including FBI and Secret Service) have gone away from the 9mm, because, among other reasons cited, they feel that rounds like the 40S&W and 357 SIG offer better penetration through barriers including automobile metal and glass.

I read an FBI report from 1996 that found that the 357SIG did not penetrate any better than 124gr+P 9mm rounds.

It would be very rare for a civilian to need to shoot through auto glass or metal, so this is mainly a question of curiousity about barrier penetration. I think most tests have shown that modern ammo that meets FBI protocols will sufficiently penetrate humans no matter what caliber is used.

I have heard people say that the 9mm bullet does not penetrate auto glass as well as a 40S&W and 45ACP because of it's smaller mass, i.e. it tends to break up more or get deflected from point of aim, even with modern bullets. Folks indicate this is why the FBI prefers a 40-caliber 180grain bullet. Supposedly, the Secret Service and other agencies chose the 357SIG due to better penetration. Then again, the 357SIG uses a 9mm caliber bullet, so I'm curious as to how the extra velocity and energy translates into better penetration through auto glass if folks like the FBI apparently believe mass is the most important thing.

When it comes to shooting through barriers, like car metal, I've heard that lighter, faster bullets do better, like the 357SIG. I am not sure about the physical differences between auto glass and metal and how bullet mass and velocity would be different through these different materials.

A number of local FBI agents have told me they feel that the 357SIG does not offer advantages over modern 9mm ammunition, and they use 40S&W because it penetrates auto glass better and will penetrate steel well enough.

Just curious about what all of your thoughts are on this...

 

[M29since14]

Bigger and heavier are constants in exterior ballistics. If you don't want to be disappointed guessing at variables, you can forget velocity and expansion. That's about all I know.

Having said that, I think in any of the calibers you mention, bullet design and construction could tip the scales in one round's favor over the others in terms of penetration.

I don't worry much about the differences between 9x19 and .357 SIG - unless using 147-gr bullets. Then the SIG seems to have a bit of an advantage.

 

[Titegroups]

I can't see how there would be any difference between the same diameter bullet 9 vs. 357 sig except for velocity and weight obviously. I think bullet shape and composition would be the critical factors in that case. IMO opinion it comes down to psi, all else being equal the smaller dia should meet the least resistance and penetrate deeper. But from a practical standpoint only actual testing will give you the answers. Anybody tried it?

 

[Kanewpadle]

I'm no expert but I do know that among the LEO agencies that use the 9MM, Gold Dot 124 +P and Win Ranger T 127 +P+ are the most street proven loads.

You can't get speed without pressure. And the 357Sig is only 100 to 150 fps faster. So who knows!

I agree that bullet design has a lot to do with it. I know people that only carry bonded ammo or Corbon DPX in any caliber because it penetrates barriers very well.

I like speed and a big bullet so I carry Win Ranger T 230 +P when I carry a 45. But according to Winchesters own testing the 230 +P isn't much better than non +P 230. Again, who knows!

 

[ElectroMotive]

Its not really a matter of velocity, mass, or ubertanium metals. Its all about bullet design. These days most modern bullets are designed to get to a certain penetration depth, and a certain expansion, through soft and hard barriers. Some do it a hair more efficiently than others, but at certain costs. Its up to the individual to weigh pros and cons, then go train and practice.

Also, keep un mind, you cannot script the gunfight that comes your way. Use a bullet that can defeat common barriers. Auto glass for instance. You may not have to shoot into a car, but what about from your car?

 

[OKFC05]

Tests conducted by Oklahoma shooting expanding handgun bullets through modern laminate windshields slanted back clearly showed the superior ability of heavier projectiles to penetrate through instead of being deflected upward. When shot straight through side glass, all that were tested passed the penetration and target test.

As a result of this test, it was recommended for handguns that 180gr Golden Saber or Gold Dot be used in the .40 S&W 180 grain loading.

In addition, rifles were authorized for OHP and other state agencies to supplement sidearms. The FMJ rifle rounds were clearly superior in car penetration to any expanding handgun rounds, so bullet design is a critical factor, as is speed of bullet.

AFAIK, the OK study is not available online.

Personally, what I got out of the study is that I can shoot out through my car window if I need to, and my 9mm or .38 are not the best for shooting through the windshield of a car trying to run me down. I do not intend to routinely carry a larger caliber or use FMJ bullets, as there are many other considerations besides shooting through windshields for most of us non-LEO who carry for personal protection.

 

[WR Moore]

Penetration is dependent upon bullet integrity and velocity. Assuming integrity, the higher velocity will penetrate deeper.

Intermediate barriers are somewhat of another issue, but the above still largely holds true. Bullet design can somewhat affect deflection.

Laminated glass tends to cause bullets to shed their jackets if the core isn't bonded to the bullet. How important this is varies according to your usage. I'll also point out that shooting at automobiles trying to hit occupants with handguns is generally ineffective.

Finally, law enforcement weapon/ammo selection if affected by many factors, politics (both internal and external) included.

I should also point out that FBI/other reports available online may or may not be edited to suit an axe to be ground. The only way you'll know is to compare a known accurate copy to the online version. This doesn't rule out possible institutional bias.

 

[StatesRightist]

Barrier penetration is part of the equation, don't lose the forest for the trees. The heaviest rounds for each caliber may penetrate better in all but the 9mm's case, but they are not always the best SD round.

The 125 gr .357 magnum is the acknowledged king of the SD world of the last 30 yrs. The heavier .357 rounds over penetrate, same goes for the heaviest .44 rounds.

The .40 155 and 165 gr rounds have the best street records, not the 180's.

In the .45, yes the 230 is king.

You completely missed the 10mm.

Another thing to note, there is little to be gained by the .357 Sig vs 9mm 124 or 127 grain rounds, while the 9mm is much more affordable to buy practice ammo for.

...and on that note, buy the caliber you shoot the best with from 9mm up, placement is key, without it, even a 12GA won't get the job done for you. That is the best lesson/conclusion you can come to.

JMOs

 

[Kanewpadle]

Its not really a matter of velocity, mass, or ubertanium metals. Its all about bullet design. These days most modern bullets are designed to get to a certain penetration depth, and a certain expansion, through soft and hard barriers. Some do it a hair more efficiently than others, but at certain costs. Its up to the individual to weigh pros and cons, then go train and practice.

Also, keep un mind, you cannot script the gunfight that comes your way. Use a bullet that can defeat common barriers. Auto glass for instance. You may not have to shoot into a car, but what about from your car?

If I gotta shoot from my car I'm runnin his butt over!

 

[CO_Kid]

When my former department went to 40 caliber, the rangemasters did a "study" which consisted of firing several samples through windshields of the dead cruisers. They found that the bonded rounds performed better across the board. They chose the Remington Golden Sabre

My current department issues the Winchester Ranger +p+. I know that in 2006, an officer shot through the windshield from the inside at someone who had just shot down another officer.

I don't know the exact shot placement on the body of the bad guy. He lived, but the hits suspended hostilities.

 

[HCH]

What about sectional density?

 

[Packard]

...I have often heard it said that police agencies (including FBI and Secret Service) have gone away from the 9mm, because, among other reasons cited, they feel that rounds like the 40S&W and 357 SIG offer better penetration through barriers including automobile metal and glass....

My understanding is that the FBI abandoned the 9mm after the Miami shootout because although the bullets killed the bad guys, they didn't stop them.

Initially they switched to 10mm but the recoil was too great for too high of a percentage of agents so they dropped back to the .40.

Concern about penetration came after the study.

The only advantage I see in having a 9mm weapon is that it has a light recoil and is cheap to shoot. From a defensive point of view the .40 is more effective.

 

[Kanewpadle]

And the 45 is even more effective.

 

[Loyaljeeper]

Honestly, I've waisted a lot of time on the same topic and failed to find a true answer I could live with. A instructor that I thought a lot of preferred 40sw over the other popular calibers. When asked why he liked it over a 45 he made a point that I think about all the time. A lot of people complain about the extra snappy recoil over a 40. His reply was if you feel more recoil your target may feel it to. I saw a good example of how poor 45 acp performed against level II body armor and decided to exit the 45 game. Truthfully carry whatever you shoot best, and will carry the most.

 

[StatesRightist]

Honestly, I've waisted a lot of time on the same topic and failed to find a true answer I could live with. A instructor that I thought a lot of preferred 40sw over the other popular calibers. When asked why he liked it over a 45 he made a point that I think about all the time. A lot of people complain about the extra snappy recoil over a 40. His reply was if you feel more recoil your target may feel it to. I saw a good example of how poor 45 acp performed against level II body armor and decided to exit the 45 game. Truthfully carry whatever you shoot best, and will carry the most.

Seriously? Neither caliber will penetrate level II body armor and the recoil thing is pure bunk. The part about shooting best I agree with, if it's .38 and up.

 

[Loyaljeeper]

Seriously? Neither caliber will penetrate level II body armor and the recoil thing is pure bunk. The part about shooting best I agree with, if it's .38 and up.

 The Chattanooga Police Dept learned how ineffective 45acp is to even level II body armor in April 2011.  I don't know if 357sig would have made a difference but it was brought up that the body armor is so much more common to find amongst criminals. The criminals outdated levelII armor barely showed signs of being struck with bullets. I don't know why but these controlled test show 357sig performing extremely well against LevelII armor. I actually had a warning when I purchased my best that it was not rated for 357mag and 357sig amongst other high velocity ammo.

YouTube - Bullet Proof Vest vs .40 .45 .357 & .308
Skip to about 13:00
Their results are about typical with everyone else's.

http://www.nist.gov/oles/upload/ballistic.pdf
Page 9 shows were LevelII is not approved for 357sig

I know it depends on each specific load and FMJ performs better than a expanding round, but even the hottest 45acp Gold Dot doesnt do what a 327fed mag or 7.62 Tokarev. I bring up the 327 because it is my next purchase.

 

[sigp220.45]

My understanding is that the FBI abandoned the 9mm after the Miami shootout because although the bullets killed the bad guys, they didn't stop them.

Initially they switched to 10mm but the recoil was too great for too high of a percentage of agents so they dropped back to the .40.

Concern about penetration came after the study.

The only advantage I see in having a 9mm weapon is that it has a light recoil and is cheap to shoot. From a defensive point of view the .40 is more effective.

The FBI never abandoned the 9mm - I was issued a Sig 226 in 1991, and the 9mm has remained an option as a privately owned weapon ever since, first in Sigs and Smiths, and now in Glocks. Quite a few guys carry Glock 26s, though the 27 is far more popular.

The ammo did change though - from 115 grain Silvertips to 147 grain JHPs, first Hydra Shoks and now 147 grain Gold Dots.

(You are right that the general issue round was changed from the 9mm to the .40, by way of the 10mm. The 9mm is still an option, and rumor has it may become the standard issue again.)

The "10mm kicked too hard" thing has been around forever, but just isn't true. The ammo gurus started with a 180 grain JHP and shot it into gelatin at ever increasing velocities until it did what they wanted. That turned out to be 950 fps. The "full power" 10mm was never issued to agents. The idea at the time was to have two power levels, like the .38 Special and the .357 Magnum. It just never worked out that way once the 1076 tanked. The 10mm lives on, though, in the MP5/10mm.

As far as the .40 goes, I think its a great cartridge. It always amuses me that it would have the moniker "Short & Weak" when it is identical (.40/180/950) to the .38/40 which has always had the reputation of a "hard shooter" and a manstopper.

I have worked three fatal police shootings, all with the bonded 180 out of Glock 22s, in the past four years. In each case the bad guys were in cars and penetration was spectacular.

 

[StatesRightist]

 The Chattanooga Police Dept learned how ineffective 45acp is to even level II body armor in April 2011.  I don't know if 357sig would have made a difference but it was brought up that the body armor is so much more common to find amongst criminals. The criminals outdated levelII armor barely showed signs of being struck with bullets. I don't know why but these controlled test show 357sig performing extremely well against LevelII armor. I actually had a warning when I purchased my best that it was not rated for 357mag and 357sig amongst other high velocity ammo.

YouTube - Bullet Proof Vest vs .40 .45 .357 & .308
Skip to about 13:00
Their results are about typical with everyone else's.

http://www.nist.gov/oles/upload/ballistic.pdf
Page 9 shows were LevelII is not approved for 357sig

I know it depends on each specific load and FMJ performs better than a expanding round, but even the hottest 45acp Gold Dot doesnt do what a 327fed mag or 7.62 Tokarev. I bring up the 327 because it is my next purchase.

I do not disagree either .357 are a tough handle for level II, I was speaking about the .40 you brought up.

I like the .327 as well. 5.7mm is the vest buster if that's what's you are after, however, vests are not very prominent day to day, but the exception. However, 33% of my practice rounds are head shots. Two to the torso, I in the head. You never know.

JMO.

 

[Kanewpadle]

Honestly, I've waisted a lot of time on the same topic and failed to find a true answer I could live with. A instructor that I thought a lot of preferred 40sw over the other popular calibers. When asked why he liked it over a 45 he made a point that I think about all the time. A lot of people complain about the extra snappy recoil over a 40. His reply was if you feel more recoil your target may feel it to. I saw a good example of how poor 45 acp performed against level II body armor and decided to exit the 45 game. Truthfully carry whatever you shoot best, and will carry the most.

Goes to show that instructors are a dime a dozen. Good one's are too few.

 

[David White]

However, 33% of my practice rounds are head shots. Two to the torso, I in the head. You never know.

JMO.

Let me know how well that works out in the real world!
Last I checked.... BG's don't stand still..