A few Questions About +P and +P+ Ammunition

[kidneyboy]

I will never understand the desire for +P ammo. Standard loads will do a fine job if properly placed. If they are not then more pressure isn't going to change anything.

I have always thought of +P and +P+ as a marketing move for the "Bigger, better, faster, stronger, harder" crowd (not there is anything wrong with that).

 

[Drail]

I agree. It's sort of like the guys who believe their stock Honda Civic will go faster if they pump 92 octane gasoline into it.

 

[CraigC]

It kinda depends on what constitutes "+P" and its application. In the case of .45Colt, for example, it's a rather significant change to double the operating pressure. Or in some cases triple. Is a 405gr at1250fps in a cartridge designed for a 255gr at 900fps constitute a mere marketing ploy? No.

 

[dogtown tom]

It kinda depends on what constitutes "+P" and its application....

"Kinda" nothing.
SAAMI has specs on what definitely is or is not "+P".
The only cartridges with a SAAMI spec for +P are 9x19, .38Special, 38 Super, .45acp and .257 Roberts. Nothing else.

If an ammunition manufacturer advertises another cartridge as +P it is purely marketing and not based on an accepted standard by anyone else. Does the velocity and pressure exceed their other loading of that cartridge? Who knows. It may be higher pressure or it may be nothing but a sales and marketing ploy.

Ever hear of subsonic .22LR? Yeah, same round as standard velocity. Different box, higher price.

 

[Coop45]

Honestly, I'm not too put out by all the legal disclaimers we see with firearms these days.

Like @JohnKSa said, some people just need those warnings to think "maybe I ought not do this".

The ammunition, and therefore the firearms, are manufactured to be safe and reliable based on known engineering standards. The legal disclaimers, when you think about it, is the company telling people this in legalese. "Operate this firearm as it was built to be operated or we will not be liable for any damage incurred".

And yet a woman used Gorilla Glue instead of hair spray.

 

[CraigC]

"Kinda" nothing.
SAAMI has specs on what definitely is or is not "+P".
The only cartridges with a SAAMI spec for +P are 9x19, .38Special, 38 Super, .45acp and .257 Roberts. Nothing else.

If an ammunition manufacturer advertises another cartridge as +P it is purely marketing and not based on an accepted standard by anyone else. Does the velocity and pressure exceed their other loading of that cartridge? Who knows. It may be higher pressure or it may be nothing but a sales and marketing ploy.

Interesting head-in-the-sand approach. That would be fine if we lived in a fantasy world where ALL ammunition companies were members of SAAMI, abided by every standard and there was absolutely NO handloading data that exceeded SAAMI maximums. That ain't reality. In reality, there is "Ruger only" .45Colt, accepted to the point that every major provider of loading data has a "Ruger only" section but there is NO SAAMI standard. So what, pretend it doesn't exist? Last I checked, there was no exclusive on "+P". Does there have to be a SAAMI standard to use the designation +P. Uh, no. It is simply a descriptor to let the user know that pressures are higher than standard. It is one that most people know what it means. It's more noticeable than an asterisk. Would you propose a completely different descriptor for higher pressure ammunition that is not recognized by SAAMI?

Ever hear of subsonic .22LR? Yeah, same round as standard velocity. Different box, higher price.

Cute. Not all subsonic ammo is simply repackaged standard velocity. In fact, there is no standard for standard velocity, any more than there is a standard for "high velocity". Running under the speed of sound is not their reason for being. It is 'usually' subsonic but in cold weather, some can break the speed of sound. Subsonic is loaded specifically to stay under the speed of sound, no matter the weather, temperature or the firearm used. I'm also unaware of any standard velocity hollowpoints. Before the subsonic revolution, all hollowpoint ammunition was "high velocity". Here's a good example, Winchester T22 is marketed as a target load but it's supersonic at 1150fps.

https://www.midwayusa.com/product/2900627313

 

[dogtown tom]

Interesting head-in-the-sand approach.

It's not my head in the sand, but those that blindly follow marketing hype.

That would be fine if we lived in a fantasy world where ALL ammunition companies were members of SAAMI, abided by every standard and there was absolutely NO handloading data that exceeded SAAMI maximums. That ain't reality.

Enough companies DO belong to SAAMI and DO abide by their standards to , well MAKE IT A STANDARD. No one says you have to be a member or have to abide by their standards, but members can't use "SAAMI" in their marketing materials.

In reality, there is "Ruger only" .45Colt, accepted to the point that every major provider of loading data has a "Ruger only" section but there is NO SAAMI standard. So what, pretend it doesn't exist? Last I checked, there was no exclusive on "+P". Does there have to be a SAAMI standard to use the designation +P. Uh, no. It is simply a descriptor to let the user know that pressures are higher than standard. It is one that most people know what it means. It's more noticeable than an asterisk. Would you propose a completely different descriptor for higher pressure ammunition that is not recognized by SAAMI?

The point of standards? You missed it years ago.
And OF COURSE there is no "Ruger only .45 Colt" SAAMI spec........those "providers of loading data" aren't manufacturers providing loaded ammunition.

And yes, SAAMI should have copyrighted the use of "+P".

Cute. Not all subsonic ammo is simply repackaged standard velocity.

I didn't write that it was. Try to follow what WAS written.

In fact, there is no standard for standard velocity, any more than there is a standard for "high velocity".

Traditionally and almost without exception, major ammunition manufacturers for decades referred to "standard velocity" as that below the speed of sound, and "High velocity" as that faster than the speed of sound. You may not like it but thats the way its been for a century.

Running under the speed of sound is not their reason for being. It is 'usually' subsonic but in cold weather, some can break the speed of sound. Subsonic is loaded specifically to stay under the speed of sound, no matter the weather, temperature or the firearm used.

Irrelevant. I was clearly referring to the SAME CARTRIDGE being marketed under different labels/packaging.

I'm also unaware of any standard velocity hollowpoints.

Again, irrelevant.

Before the subsonic revolution, all hollowpoint ammunition was "high velocity". Here's a good example, Winchester T22 is marketed as a target load but it's supersonic at 1150fps.

https://www.midwayusa.com/product/2900627313

And thank you for proving my point. Again, I mentioned SUBSONIC, not "target load".

 

[CraigC]

So where's the rub? You don't want companies to use the "+P" descriptor if there's no SAAMI designation for such? What then? What does an AMMUNITION MANUFACTURER have your permission to use? More importantly, why? How is that helpful?

As I said, there is no industry standard for standard velocity. Period. While most of it is, only match ammo is deliberately kept subsonic. If it automatically is supposed to refer to subsonic, where is this written? Or is it just your perception?

The Winchester T22 does not prove your point, it refutes. Target/match ammo is usually intentionally, very deliberately kept subsonic. That one isn't. Within some brands, such as CCI, their match ammo is just carefully selected from their standard velocity ammo. In other words, if it's "standard velocity", you don't really know what you're getting. Subsonic is very deliberately loaded to subsonic velocities.

I reckon anything you can't directly respond to is deemed "irrelevant". That's very convenient.

 

[Terry G]

Again, the Federal 9 MM 124 grain +P+ safe to shoot in modern handguns? I don't mean range shooting, just a magazine or two and the rest for self defense?

 

[LightninST]

I agree. It's sort of like the guys who believe their stock Honda Civic will go faster if they pump 92 octane gasoline into it.

But 92 octane is Hi Test fuel ️ they must be using the wrong Oil !
+P & +P+ ammo is fun but I would only use it for big critter defense.
I like 357s but also shoot a lot of 38s , why beat yourself up YOMV

 

[DustyGmt]

Again, the Federal 9 MM 124 grain +P+ safe to shoot in modern handguns? I don't mean range shooting, just a magazine or two and the rest for self defense?

I obviously don't know as much as the reloaders, so I won't elaborate any further than to say I know alot of people do, and that I have in my glocks with 9BPLE. The winchester 9BPLE specifically was really popular with people and LEO agencies and have read threads of people dumping cases through their glock. I would guess that for your purposes, shooting a mag or two to test, you would most likely be fine.

But, to appeal to the wisdom that's here, and to be cautious, you might very well do best to stick within known parameters and manufacturer disclaimers or whatever. If I was you I would shoot it. I think it will be fine. Your call.

 

[Hangingrock]

When Smith&Wesson introduced the M640-38Spec were marked "TESTED FOR +P+". At that time there was no industry standard for +P+ thus follow on production eliminated the wording.

 

[RetiredUSNChief]

Again, the Federal 9 MM 124 grain +P+ safe to shoot in modern handguns? I don't mean range shooting, just a magazine or two and the rest for self defense?

"You pays your money and you takes your choice."


"Safe" is relative, not absolute. It's ALWAYS relative.


The deal with "standards", in the context of this thread, is that manufacturing firearms to a known ammunition standard for a given cartridge results in a firearm which has an "acceptable" safety margin over the service life of the weapon. In layman's terms, this means you are extremely unlikely to have a premature mechanical failure or catastrophic failure of the weapon under normal use.

If you EXCEED the chamber pressures the firearm is built to, then you DECREASE the safety margin. This means you are more likely to have a premature failure of the weapon because you are operating it with higher chamber pressures than it was designed to be routinely operated at.

If a firearm is actually designed for +P ammunition, then obviously using +P ammunition is perfectly acceptable.

If a firearm is NOT designed for +P (and by definition +P+) ammunition, then you ARE operating at a lower margin to safety.


What you are asking in your posting is for an absolute answer to "is it safe". There is no absolute answer, in terms of a line of demarcation in which one can say "cross this pressure and you WILL have a failure/stay below it and you WON'T have a failure".


Let's touch just a tiny bit on a subject called "Fracture Mechanics".

Fracture Mechanics is the study of crack propagation in metals. It is concerned with how metals may fail under a stress in order to characterize resistance to fracture. There are two main modes of failure: ductile (the metal bends) or brittle fracture (the metal cleanly snaps, with no evidence of bending).

The point at which failure occurs, whether ductile or brittle fracture, changes for a given metal/alloy under a variety of conditions as well as over the service life of the metal. Change a metals' temperature, for example, and you change the point at which it will fail at and, potentially, the failure mode.

And the failure point/mode may change over life due to cyclic stress. When you repeatedly apply stresses (thermal and pressure), you may change the metal's fracture toughness (the ability to resist crack propagation) through a variety of reasons, such as the size of the microscopic cracks already present in the metal's crystaline structure or changes to the metal's crystaline structure itself.

Those who are seriously into reloading can tell you that hardening of brass cases through repeated reuse is a real thing and eventually leads to cracks unless they are annealed at some point.


WHAT DOES ALL THIS MEAN?

What it means it the answer to your question is not only a problem with obtaining a precise answer to your question, but that the answer itself may change over the service life of your firearm.


BOTTOM LINE:

Your firearm is not likely to have a catastrophic failure at design +P pressures. But you WILL be adding more stress to your firearm which WILL lead to a premature mechanical failure at some point.

Your firearm is not likely to have a catastrophic failure at +P+ pressures SO LONG AS THOSE PRESSURES REMAIN BELOW PROOF PRESSURES AND ARE NOT OF ROUTINE USE.

But the problem with +P+ is that there is no quantitative definition of what constitutes +P+ pressures. SAAMI does not define any pressure range or limit associated with +P+. They DO, however, define proof pressures.

By convention, it's generally assumed that +P+ is greater than the defined SAAMI +P pressures, but less than proof pressures. But the rub is "assumed". There's an old saying that when you "assume" something, you make an "*ss" out of "u" and "me". The plain fact of the matter is that there is no defined upper limit and therefore +P+ can not only approach, but exceed proof pressures. This is bad juju. The only way to know what the actual pressures a manufacturer of such ammunition is would be to contact them and ask...and they may or may not provide that information to you.


My personal opinion is that there are a great many choices in quality self-defense ammunition out there which is more than adequate for self-defense. There is very little, if any, benefit to shooting +P or +P+ ammunition.

But as I said above:

"You pays your money, you takes your choice."

 

[dogtown tom]

So where's the rub? You don't want companies to use the "+P" descriptor if there's no SAAMI designation for such?

Again, SAAMI DOES have a designation for +P ammunition in certain cartridges. A manufacturer using the +P designation for cartridges such as .25acp/.32acp/.40/etc has no standards other than his own. He's doing it for marketing and sales purposes. That manufacturer is using the reputation of SAAMI specs for his own benefit and is profiting off an ignorant consumer.

Such marketing hyperbole may present a danger to the user. The firearm may be a hundred years old with suspect metallurgy and a design that makes the use of overpressure cartridges dangerous.

What then? What does an AMMUNITION MANUFACTURER have your permission to use? More importantly, why? How is that helpful?

Oh good grief. Ask yourself one simple question.........Why is there a need for SAAMI? Standards matter. Safety matters. No manufacturer is required to use SAAMI specs, but its a marketing and liability nightmare if they don't.
If every ammunition manufacturer decided they would use their own standards for pressure, case dimensions and testing the consumer would suffer. You should recognize that.

As I said, there is no industry standard for standard velocity. Period.

And no one said otherwise. Are you standing in front of a mirror?

While most of it is, only match ammo is deliberately kept subsonic. If it automatically is supposed to refer to subsonic, where is this written? Or is it just your perception?

I don't give a hoot about "match ammunition" and AGAIN for the inth time its irrelevant. I wrote "Ever hear of subsonic .22LR? Yeah, same round as standard velocity. Different box, higher price." And that true. Yeah, I know not every manufacturer does it but Federal does and Remington did.

The Winchester T22 does not prove your point, it refutes. Target/match ammo is usually intentionally, very deliberately kept subsonic.

Again, (see a pattern here?) I don't give a hoot, a care, nor an iota of concern about how a manufacturer brands, labels or markets their "match ammo". Again, I did not make any reference to "match ammo" and any further discussion of "match ammo" should be in front of your bathroom mirror.

That one isn't. Within some brands, such as CCI, their match ammo is just carefully selected from their standard velocity ammo. In other words, if it's "standard velocity", you don't really know what you're getting.

As you said there are no SAAMI standards. Now by your own admission it appears "match ammo" is reboxed standard velocity ammo.

Subsonic is very deliberately loaded to subsonic velocities.

No kidding?

I reckon anything you can't directly respond to is deemed "irrelevant". That's very convenient.

Go argue with the mirror. If you dislike the content of my posts, arguing with the content of my post. You didn't.

 

[CraigC]

Again, SAAMI DOES have a designation for +P ammunition in certain cartridges. A manufacturer using the +P designation for cartridges such as .25acp/.32acp/.40/etc has no standards other than his own. He's doing it for marketing and sales purposes. That manufacturer is using the reputation of SAAMI specs for his own benefit and is profiting off an ignorant consumer.

Are you being intentionally obtuse or just trying to win an argument? You did not answer my questions. The manufacturers in question are not using +P for marketing. They're using it as a warning to the consumer. Did you even look at the screenshot I shared? The Garrett "Redhawk only" loads are marketed as "+P" because they're FORTY FIVE THOUSAND PSI. Not as a marketing ploy to dupe "ignorant consumers". It's a warning that hopefully keeps them out of inappropriate guns. We're not talking about 9mm or .38Spl +P but a real, tangible, significant difference.

Again, if +P triggers this, what is your proposed alternative and how is it better? You don't really have an answer to this question so I expect you to ignore it again.

I don't know what Remington subsonic you're looking at but I have several thousand rounds of it and it's all hollowpoint. For which there is no "standard velocity" equivalent. The only Federal I see is their "suppressor" ammo that is 45gr, also with no "standard velocity" equivalent.

 

[buck460XVR]

My questions will be a lil scattershot so please bear with me but what I take from that is that anything we see marketed as +P today is just ammo loaded to pre 1972 levels, most likely because of lawyers covering their clients from mishaps involved with poor quality and antique guns,, etc.. so if I wanted a truly hot +P loading I would need to load my own or buy +P+ ?

Also, if I have a gun made before 1972, and the old instruction manual says not for use with +P ammunition, would it be safe to shoot +P ammo in it because it's manufacture predates the new standard?

If you have a gun with specific instructions NOT to shoot +p ammo in it, that tells me the manufacturer was aware of +p ammo being on the market before there were SAAMI standards. Not all calibers have been watered down and those that were, are because better testing methods showed pressures created by the ammo was really more than the gun was spec'd for. Sometimes ammo was watered down because standard ammo of the day wore them out prematurely. In the case of .460 and .500 ammo, factory ammo is slightly watered down form original to make extraction easier. Was a time when bullets needed to be pushed extremely hard in order to get terminal performance. Modern bullets are more diversified and designed to perform at different velocities. .380 and 9mm bullets are prime examples.

My question is.....Why do you think you need +p+ ammo? Is it that the game you are hunting is too tough for standard velocity ammo? Are you looking to get more range or better terminal performance downrange? Why is standard ammo inappropriate for your purpose? Are you trying to make your 9mm into a .357 mag? Was a time when folks had to load hot because .357 was the largest handgun caliber available. Want to hunt elk or grizzly bear with it(and folks did) you loaded it hot and didn't worry about wearing out the gun in 500 rounds. Nowadays we have larger calibers that are as popular as .357 and will give the terminal performance of a hot loaded .357 with anemic plinking velocity ammo. Most folks now just go up in calibers instead of going hot.

Your gun, your choice. All of the owners manuals I got with my new guns told me not to shoot reloads in them. Most all of my ammo is my own reloads. But I reload safely and stay within known parameters. The warnings are intended so one does not shoot ammo that goes beyond known parameters. Kinda like some of the +p and +p+ ammo out there. So many new reloaders out there are in the quest for the fastest ammo they can make. I quest for the most accurate and most of the time that is well below anything labeld as +p or +p+.

 

[dogtown tom]

Are you being intentionally obtuse or just trying to win an argument? You did not answer my questions.

Well, I believe I did. It's likely not the answer you wanted. Thats okay.

The manufacturers in question are not using +P for marketing. They're using it as a warning to the consumer.

It's both.

Did you even look at the screenshot I shared? The Garrett "Redhawk only" loads are marketed as "+P" because they're FORTY FIVE THOUSAND PSI. Not as a marketing ploy to dupe "ignorant consumers". It's a warning that hopefully keeps them out of inappropriate guns. We're not talking about 9mm or .38Spl +P but a real, tangible, significant difference.

Sigh. It's a marketing ploy to sell ammo. A consumer that sees such ammunition on a shelf rarely looks at the companies website, much less reads the fine print on the box. Don't believe that? Then come sit next to me for an hour as people fill out the 5573 and skip the same questions over and over. Answer the phone for me and explain to the guy who just jammed up his S&W Shield 9mm with 9mm Mak ammo.

Garrett decided that 45K psi is "+P"......what about the next manufacturer whose ".45Colt +P" is 55k psi and may/may not have such a warning?..........both are ".45 Colt +P". See the problem?

Again, if +P triggers this, what is your proposed alternative and how is it better? You don't really have an answer to this question so I expect you to ignore it again.

Uhhh..............maybe SAAMI develops a standard for +P in a wider range of cartridges? It ain't rocket surgery.

I don't know what Remington subsonic you're looking at but I have several thousand rounds of it and it's all hollowpoint. For which there is no "standard velocity" equivalent. The only Federal I see is their "suppressor" ammo that is 45gr, also with no "standard velocity" equivalent.

What you "see" today, isn't necessarily what was manufactured in the past nor what may be manufactured or marketed next week.

 

[jmorris]

It's not my head in the sand, but those that blindly follow marketing hype.

Are you trying to say this ammo is no good for zombies? (Insert rolling eyes face)

 

[nofendertom]

Before I would use +P+ I would get a bigger gun.

 

[CraigC]

Well, I believe I did. It's likely not the answer you wanted. Thats okay.

No, you didn't and I see you won't. You seem to be more concerned with saving face and winning.

It's both.

It isn't. I'm pretty sure people aren't grabbing 405gr .45Colt loads off the shelf just because it says +P on it. They're buying it because of what it does. You're mixing two completely different concepts because you work in a gun shop and see dummies walking in and out with off the shelf +P ammo. We're not talking about the same thing. I see the difference, you do not.

Garrett decided that 45K psi is "+P"......what about the next manufacturer whose ".45Colt +P" is 55k psi and may/may not have such a warning?..........both are ".45 Colt +P". See the problem?

It isn't a problem. In this case, "+P" isn't supposed to represent a known quantity. It's merely a red flag, a warning. A sign to look deeper. Again, you are a jaded cynic, judging by the lowest common denominator.

Uhhh..............maybe SAAMI develops a standard for +P in a wider range of cartridges? It ain't rocket surgery.

That will never happen. Here is where it pays to know what you're talking about. These loads are aimed at Rugers. Ruger has NEVER condoned or endorsed the use of ANY loads that are over SAAMI pressure standards, purely for liability reasons. They have no reason to change their position, especially now that there are Ruger .45's that are not safe for "Ruger only" loads. S&W and Colt make no such guns so they also have no reason to want to change. So who will be voting for such a change? No, there will never be an official .45Colt +P. Luckily, those of us who are not counted among the lowest common denominator, can count on our own judgment to know what loads go in what guns.

What you "see" today, isn't necessarily what was manufactured in the past nor what may be manufactured or marketed next week.

My frame of reference is not Google or last week. Again, I have never seen Remington subsonic that was not a hollowpoint. Actually looks just like their Cyclone, loaded to lower velocity.

 

[dogtown tom]

No, you didn't and I see you won't. You seem to be more concerned with saving face and winning.

Well, be so kind as to ask that question again. I thought I answered every question asked.

It isn't. I'm pretty sure people aren't grabbing 405gr .45Colt loads off the shelf just because it says +P on it. They're buying it because of what it does.

Really? People buy whatever they can get right now. If they aren't astute or knowledgeable enough to know that those .405's might only be safe in Rugers....who's fault is that?
And good grief man, you are stuck on that one load from one boutique ammo manufacturer. Think beyond that.

You're mixing two completely different concepts because you work in a gun shop and see dummies walking in and out with off the shelf +P ammo. We're not talking about the same thing. I see the difference, you do not.

I don't work in a gun shop.
Gun forums are rife with folks that don't understand anything but 9mm = 9mm. That there is 9x19, 9mm Short, 9mmACP, 9mmMak, etc shows that many in the gun buying public aren't as sophiscated as you in knowing that the Garrett round is unsafe for anything other than Ruger Redhawlks.

It isn't a problem. In this case, "+P" isn't supposed to represent a known quantity. It's merely a red flag, a warning. A sign to look deeper. Again, you are a jaded cynic, judging by the lowest common denominator.

Well, yeah it is......its the recognised designation by SAAMI for ammunition that is over pressure and IS a known quantity. Thats why I have problems with JimmyJoe Specialty Ammunition & Bait cranking out .25acp +P ....................its dangerous.

Jaded cynic? Maybe, but I deal every day with the gun buying public, but I can't go to WalMart or Academy with them to buy ammo. And FYI....that lowest common denominator encompasses a few million people.

That will never happen. Here is where it pays to know what you're talking about.

How do you know it will never happen? If you knew what YOU were talking about you would know how SAAMI works.

These loads are aimed at Rugers. Ruger has NEVER condoned or endorsed the use of ANY loads that are over SAAMI pressure standards, purely for liability reasons. They have no reason to change their position, especially now that there are Ruger .45's that are not safe for "Ruger only" loads. S&W and Colt make no such guns so they also have no reason to want to change. So who will be voting for such a change? No, there will never be an official .45Colt +P. Luckily, those of us who are not counted among the lowest common denominator, can count on our own judgment to know what loads go in what guns.

That's called a clue....a clue as to why a manufacturer shouldn't be so quick to toss around a +P designation willy nillly.

 

[DustyGmt]

My question is.....Why do you think you need +p+ ammo?

I really never got too jazzed up about +P or +P+ and typically only carry or shoot standard pressure. I've seen enough testing that clearly demonstrated no real appreciable benefit and the difference, if any, was just harder on your equipment so no real upside. I still am not entirely clear as to how +P could be a benefit to me. I used to carry it in my subcompacts because of the shorter bbl's but I guess I reasoned that out with bad information.

I was just basically laying awake late one night just thinking about +P and knew this was a good place to ask about it.

 

[DustyGmt]

Over the years I can't even track all the outrageous things I've heard people say about guns, ammo, etc... I've heard people qualify their choice of ammo by disparaging another and perpetuating myths. "Oh I carry .40S&W because 9mm won't penetrate a windshield".

I've actually heard people say that type of thing and I had to laugh because in an episode of Breaking Bad the agent says "if you're gonna bring a gun, you gotta bring enough gun. Now the 9mm, unless we're talking +P+ loads, will bounce right off the window", and the infinitely stupid "if you can't get it done with 6, you shouldn't even carry a gun" that one is a beaut. Its funny because I actually know of people who think that.

There was a good bit posted in this thread that I didn't know. Basically the extent of my knowledge on +P was hotter/faster, I conducted some of my own tests and found that +P was not as special as I may have previously thought. There was only one brand of +P that distinguished itself from the others. Hornady critical duty 9mm 135+P and 135 standard. The +P penetrated a lil over an inch deeper and when the JHP expanded the petals peeled all the way back toward the base. Just an anecdote. No real scientific method applied. Just checking things out for fun.

Thanks to those who posted. To the guys having the rigorous and committed debate, I think you've both made good points. Thanks for the info.

 

[fxvr5]

Gun forums are rife with folks that don't understand anything but 9mm = 9mm. That there is 9x19, 9mm Short, 9mmACP, 9mmMak, etc . . .

Never heard of a 9mm ACP.

 

[RetiredUSNChief]

Never heard of a 9mm ACP.

An archaic term for 9mm short (9mm kurtz) or .380 auto as it's more commonly known.