Doubts about 9mm

[GlorifiedMailman]

No. There are diminishing returns.

The new technology greatly improved 9mm, slightly improved .45 - basically bringing both on par with .40 S&W. .40 performance has stayed flat.

The real advance in ammunition technology was not expansion or bigger wound channels, though expansion has become more reliable. It's barrier blind ammunition that gives "Goldilocks" performance - that 12' to 18' of penetration needed to reach the vital structures in the human body that cause incapacitation without exiting the body. What Kyle DeFoor refers to as "timers" (significant blood loss) and "switches" (Brain, brain stem, etc)

The performance of the 9mm Silver tip in Miami clearly shows this. The issue was failure to adequately penetrate and reach the heart after passing through an intermediate barrier (arm), not failure to create a large enough wound channel.

Modern barrier blind ammunition performs in this "sweet spot" even when it passes through intermediate barriers, whether vehicles, drywall, or bones. Too much penetration and the bullet punches a hole without dumping it's kinetic energy and now you have to worry about what it will hit next. Too little penetration and you create superficial wounds that do not reach the structures needed to incapacitate as seen in Miami.

.45 ACP is actually a poor performer on intermediate barriers, even with modern ammunition, because of the large frontal area of the bullet.

Prior to barrier blind bullets, 9mm rounds were usually either somewhat anemic 147 grain JHP's that were too slow to expand or penetrate reliably or fast light 115 grain bullets that either over expanded, limiting penetration when they hit flesh, or broke up when they hit intermediate barriers leaving the smaller pieces insufficient mass to penetrate adequately.

Prior to barrier blind bullets .40 and 45 had the mass to stay in one piece after passing through intermediate barriers, if the .45 made it through. .40 S&W was actually a "sweet spot" prior to barrier blind bullets as it had better penetration through intermediate barriers than .45 acp but still had enough mass to stay in one piece and adequately penetrate after passing through barriers.

Even with modern bullet technology few agencies using 9mm are carrying 115 grain. Most LE agencies carrying 9mm are carrying 124 or 147 grain +P or +P+ loads. A faster heavier bullet that stays in one piece after passing through barriers and penetrates adequately even when it expands in soft tissue.

As a youngster I started my career with a Ruger .357 revolver and could not wait to swap it out for a SIG P-220 with "by God" .45 caliber 185 grain JHP. When was that you might ask? Well, to quote Bob Valdez in Valdez is coming "Before I know better.

Thank you so much for this response. This actually hits about every nail on the head. Contrary to claims, I'm not seeking to just keep this subject going indefinitely. I simply wanted help with some questions that have come up after studying the wealth of information in this site and others.

This pretty much puts to rest any doubt in my mind. I will continue to carry, train, and practice with 9mm as I have before. I probably won't ever completely get rid of every .45, but they're largely retired now as I focus my efforts on my two Glock 19 Gen 5's.

[the Schwartz]

I notice my response came right after one of your posts and it was not directed at you as I did not quote you.

This is one of those bandwidth wasting threads that honest people are trying to help somebody who looks like they're trying to see how many replies they can get to a thread or how long they can keep it going.

In today's world with the information out there it is idiotic to discuss the slight variances in service caliber ammunition.

Therefore anyone doing that is just baiting or hasn't done any research. Again a waste of bandwidth.

With any luck at all this thread will descend into pressure spikes and defence of clear gel.

This is the type of discussion that drives the SMEs away instead of helping us.

There is a tremendous amount of misinformation and disinformation on the topic that contributes to the "noise" obscuring the "signal".

[Det1397]

Thanks HCM and the other SMEs that have responded- outstanding information... refer to Doc ( https://pistol-forum.com/showthread....f-Defense-Ammo ) and let's move on. Remember to practice, then practice more- bullet placement is KING. My one (and only OIS) back in 1999 involved a subject that was high enough on heroin and cocaine that he should have been unconscious- but he wasn't.
My G19 was loaded with old school Federal 124 grain +p+ Hydra Shok JHP. Thankfully, due to my extensive training and practice, I was able to place three rounds exactly where they needed to go and I went home to my wife and kids that day.
Remember to practice, then practice more.

[Totem Polar]

Not much to add except to tip my hat to @HCM for a pretty damn good "nutshell’ summary of a long-debated, and thankfully, much-researched topic.

[BBMW]

I buy part of this, necessary depth of penetration, and barrier blindness for expansion (especially for LE), but I just don't buy the fact that expanded diameter doesn't matter, or that it has a point of diminishing returns. If that was the case, FMJ would would rule. It doesn't. A bullet with a bigger diameter destroys more tissue, causing more bleeding, and increases the chance of hitting something important with any give shot. If you don't hit one of the "switches" (which is exceedingly difficult in a combat situation), getting the target to bleed out more quickly is critical. And note that a small increase in expanded diameter creates a large increase in frontal area.

No. There are diminishing returns.

The new technology greatly improved 9mm, slightly improved .45 - basically bringing both on par with .40 S&W. .40 performance has stayed flat.

The real advance in ammunition technology was not expansion or bigger wound channels, though expansion has become more reliable. It's barrier blind ammunition that gives "Goldilocks" performance - that 12' to 18' of penetration needed to reach the vital structures in the human body that cause incapacitation without exiting the body. What Kyle DeFoor refers to as "timers" (significant blood loss) and "switches" (Brain, brain stem, etc)

The performance of the 9mm Silver tip in Miami clearly shows this. The issue was failure to adequately penetrate and reach the heart after passing through an intermediate barrier (arm), not failure to create a large enough wound channel.

Modern barrier blind ammunition performs in this "sweet spot" even when it passes through intermediate barriers, whether vehicles, drywall, or bones. Too much penetration and the bullet punches a hole without dumping it's kinetic energy and now you have to worry about what it will hit next. Too little penetration and you create superficial wounds that do not reach the structures needed to incapacitate as seen in Miami.

.45 ACP is actually a poor performer on intermediate barriers, even with modern ammunition, because of the large frontal area of the bullet.

Prior to barrier blind bullets, 9mm rounds were usually either somewhat anemic 147 grain JHP's that were too slow to expand or penetrate reliably or fast light 115 grain bullets that either over expanded, limiting penetration when they hit flesh, or broke up when they hit intermediate barriers leaving the smaller pieces insufficient mass to penetrate adequately.

Prior to barrier blind bullets .40 and 45 had the mass to stay in one piece after passing through intermediate barriers, if the .45 made it through. .40 S&W was actually a "sweet spot" prior to barrier blind bullets as it had better penetration through intermediate barriers than .45 acp but still had enough mass to stay in one piece and adequately penetrate after passing through barriers.

Even with modern bullet technology few agencies using 9mm are carrying 115 grain. Most LE agencies carrying 9mm are carrying 124 or 147 grain +P or +P+ loads. A faster heavier bullet that stays in one piece after passing through barriers and penetrates adequately even when it expands in soft tissue.

As a youngster I started my career with a Ruger .357 revolver and could not wait to swap it out for a SIG P-220 with "by God" .45 caliber 185 grain JHP. When was that you might ask? Well, to quote Bob Valdez in Valdez is coming "Before I know better.



https://www.imdb.com/title/tt0067921...ters/nm0000044

[GlorifiedMailman]

I've also seen DocGKR and others state that, if forced to use FMJ, they would choose larger calibers like .45 Auto. That would make it seem like there actually is enough of a difference to matter between the diameters of 9mm and .45. I was always under the impression that the difference between 9mm and .45 FMJ wasn't that much, and the increased capacity, lower recoil, etc of 9mm made it better.

[0ddl0t]

A bullet with a bigger diameter destroys more tissue, causing more bleeding, and increases the chance of hitting something important with any give shot. If you don't hit one of the "switches" (which is exceedingly difficult in a combat situation), getting the target to bleed out more quickly is critical. And note that a small increase in expanded diameter creates a large increase in frontal area.

FMJ diameter:
9mm = 9mm
.40 = 10mm
.45 = 11.4mm

Expanded JHP diameter:
9mm ~= 15mm
.40 ~= 17mm
.45 ~= 19mm

But the typical artery is ~3mm wide with the largest being 10-25mm. Does a 19mm bullet really do all that much more damage to a 10mm artery than a 15mm bullet?

[HCM]

I buy part of this, necessary depth of penetration, and barrier blindness for expansion (especially for LE), but I just don't buy the fact that expanded diameter doesn't matter, or that it has a point of diminishing returns. If that was the case, FMJ would would rule. It doesn't. A bullet with a bigger diameter destroys more tissue, causing more bleeding, and increases the chance of hitting something important with any give shot. If you don't hit one of the "switches" (which is exceedingly difficult in a combat situation), getting the target to bleed out more quickly is critical. And note that a small increase in expanded diameter creates a large increase in frontal area.

You can not buy that the earth is round but that doesn’t make it flat. Living tissue is elastic. Unless it is the rare situation where the diameter is the difference between nicking or missing a major blood vessel there is no practical difference.

The primary negative issue with FMJ is over penetration. Expanded JHP often cuts as well as crushes as it passed through tissue but that a difference in the mechanism of injury. In that case a 9mm JHP expanded to 45 could be slightly more effective than a 45 FMJ even though they are the same size. But the difference between expanded 9mm and expanded 45 acp are negligible.

[HCM]

I've also seen DocGKR and others state that, if forced to use FMJ, they would choose larger calibers like .45 Auto. That would make it seem like there actually is enough of a difference to matter between the diameters of 9mm and .45. I was always under the impression that the difference between 9mm and .45 FMJ wasn't that much, and the increased capacity, lower recoil, etc of 9mm made it better.

How long ago ?

Last I recall he said he would have no issue carrying 9mm FMJ if someone were giving him 10-20k a year of it to maintain real proficiency.

Regardless it comes down to shot placement trumping everything. And no matter how good you are even if you are Rob Latham in a real fight someone could get lucky or you could it be unlucky for that one in 1 million time. There are no guarantees and obsessing over magic bullets and which service caliber is better is a gigantic waste of time. If someone is giving you free 40 or 45 ammo go shoot it and don’t look back. If you are paying for your own ammo 9 mm will get you more training and practice which equals greater proficiency and a Greater chance of making an affective hit when you need to.

That’s as good as it gets.

There are plenty of individuals in the law-enforcement military and Intel community who work overseas and are required to use whatever equipment and ammunition is locally provided. If guys can run around Africa and southwest Asia with Glock 19 full of FM J and not get killed in the streets I’m pretty sure you’re OK here conus. Barrier blind JHP ammo is nice to have but it is not essential

It is very much the Indian not the arrow.

[HopetonBrown]

GlorifiedMailnan and BBMW, would you two care to share your average 25y B8 score or FAST test, because I'm curious if you put equal effort and energy into shooting as you do in caliber debates.