.45 ACP +P

[9x18_Walther]

Pretty well versed in ballistics, but I seem to be missing something here.

For the longest time, most people recommended 9mm loadings in +P, yet rarely do I see mention of +P loadings in .45 ACP.

The pressure increase between +P and the standard loading in both calibers is roughly 9%.

What is the purpose of .45 ACP +P, or should I rephrase the question, does +P in 9mm matter?

Does this have to do with the inefficient 9mm JHP designs of the past?

 

[Limnophile]

I can only assume that +P loadings are an archaic remnant of paleoplumbic JHP designs, as +P loads from quality manufacturers often fail to meet IWBA minimum penetration criteria; eg:

.

Note that the 9 Luger +P+ 115-gr Gold Dot, the 9 Luger +P 124-gr Gold Dot, and the .45 Auto +P 200-gr Gold Dot loads all fail to meet the IWBA minimum criterion of 12.5 inches in bare gel. They all meet the IWBA heavy clothing minimum criterion of 13.0 inches, but the 9 Luger 147-gr and .45 Auto 230-gr Gold Dots meet both criteria. Heavy-for-caliber seems the way to go (.40 S&W is an exception, as the 165-gr load has the best penetration).

Overpressure loads seem analogous to fishing lures that catch fisherman instead of fish. Why buy more bang to get more recoil, worse accuracy, more wear and tear on your gun, and inadequate penetration?

 

[TunnelRat]

I can only assume that +P loadings are an archaic remnant of paleoplumbic JHP designs, as +P loads from quality manufacturers often fail to meet IWBA minimum penetration criteria; eg:

Note that the 9 Luger +P+ 115-gr Gold Dot, the 9 Luger +P 124-gr Gold Dot, and the .45 Auto +P 200-gr Gold Dot loads all fail to meet the IWBA minimum criterion of 12.5 inches in bare gel.

I'd point out that on that chart the only 9mm that meets the standard you list is the 147 gr. The failure isn't restricted to just +P loadings. Interestingly the 124 gr +P 9mm does better in bare gelatin than the standard velocity of the same weight, though both pass the heavy clothing criteria. Maybe the cross-sectional area of the projectile comes into play?

 

[Clark]

The 45acp with handloads is capable of 44 magnum power.
What holds the cartridge back is:
1) case support
2) recoil

The web of the 45acp case is 0.180" thick and one of my old 1911 barrels has feed ramp intrusion all the way to 0.225". That leaves 0.045" of thin unsupported case wall. A para ord P10 has 0.235", leaving 0.055" unsupported.

While some of my 45acp pistols have case support at 0.180".
What stops them in a work up from going to 460 Rowland levels and beyond?
Recoil.

~Half the recoil momentum moves the hand and frame, but half goes into the slide velocity relative to the frame. The energy in that slide momentum must be stored in the recoil spring(s). One would need a heavy slide and serious recoil springs to make that work well, without a hefty remainder hammering the slide into the frame.

The 9mm cartridge is capable of 357 mag performance, but just not practical.
The 9mm has a 0.160" case web and most 9mm pistols have no more than 0.190" feed ramp intrusion.
Case support is not the problem.
Mostly recoil holds the 9mm back.
I have some 9mm handloads that if I fire 3 shots, my hand hurts for an hour.
If I build a triple recoil spring assembly, the slide moves forward too fast to pick up the next round. I then need to put two magazine springs in parallel. The 9mm then takes superman to load the magazine and the hulk to chamber a round. All this does is tune up a Glock 19 for 9mm+P. And the G19 trigger cannot reset that fast either. It requires the NY trigger.
The 357 mag level performance would require a much heavier slide.

 

[44 AMP]

For the longest time, most people recommended 9mm loadings in +P, yet rarely do I see mention of +P loadings in .45 ACP.

I believe 9mm+p came about as a result of the widely perceived need for improvement in the performance of the 9mm Luger round. There was no such widely perceived need for that improvement in the .45ACP.

The pressure increase between +P and the standard loading in both calibers is roughly 9%.

This is the standard adopted by SAAMI (Sporting Arms & Ammunition Makers Institute)

What is the purpose of .45 ACP +P, or should I rephrase the question, does +P in 9mm matter?

The purpose of any +P load is to provide some kind of improvement in performance, using higher than standard pressure to give increased velocity, (hopefully) resulting in some significant degree of improvement.

Does it matter? A lot of people believe so.

Does this have to do with the inefficient 9mm JHP designs of the past?

They are part of the history, yes, absolutely.

To understand why we have what we have today, you need to look at the history, AND you need to understand that the history includes both physical reality, and people's perceptions of reality. It is the perceptions of reality that drive commercial markets more than anything else.

Perceptions and beliefs always have some physical reality as a base, but can, and often do grow to the point where their connection to physical reality is tenuous, or even non-existent.

The really astonishing thing is some people actually believe even the most amazing tales. "9mm won't stop nobody, no matter what", and "a .45 will knock a man down from a hit on the finger", are examples taken to foolish extremes.

Back in those "stone age" days, handgun ammo came in essentially two flavors from the factories. FMJ for semi auto calibers, and lead (generally lead round nose (RNL or LRN depending on who is writing). If you wanted something else, you handloaded. Compared to those days, today, we are spoiled rotten.

A couple questions (lovely chart, btw),

Who is IWBA? And why does their standard matter?

Why buy more bang to get more recoil, worse accuracy, more wear and tear on your gun, and inadequate penetration?

Are you meaning to say this applies to all +P loads?? If so, I'd say there are too many variables at work to make that an accurate statement.

It is an interesting chart, and I'm sure it accurately shows the results obtained from the testing, but remember, it only accurately applies to the specific loads used in the testing.

I found it interesting that the 125gr .357 bullet out penetrated the same weight bullet, at higher speeds, from both the 9mm+P and the .357 Sig, in every category, except after going through 20 gauge steel and laminated safety glass.

Both the .357 loads shown are listed at just BELOW 1200fps, and yet they have the best penetration numbers other than the hard barrier penetration categories (steel, glass), and in those groups are only beaten by a couple of loads, in other calibers (which are moving ~100-200fps FASTER.

When a 125gr .357 at 1189fps penetrates significantly more than a 125gr .355" bullet at 1235fps (9mm+P) AND a 125gr .355 bullet at 1379fps (.357 Sig), there is more at work than just bullet velocity (pressure).

Bullet construction matters. More than just a little.

 

[lamarw]

Agree with the responses. I am just not a +P type of guy. I can't see it, since if I need perceived more power then I will grab a more powerful firearm.

I reload 99% of my ammunition and never exceed beyond normal limits into hot ammunition. I can't see the need to abuse my firearms. As an example I have numerous .38 Special revolvers of which some is older and not recommended for +P. Some is new and will handle it. I just reload them all the same which are safe in older and the newer. I can always grab my .357 Magnum.

If my .45 ACPs are not enough, then grab my .45 Colt. Not expecting the need for anymore, or I will grab one of my 12 gauge shotguns.

 

[jmhyer]

I have always subscribed to the "go heavy" principle for SD ammo. Generally speaking, go with the heavier JHP bullet in whatever caliber you are shooting. In 9mm, that's 147gr. For 45ACP, that's 230gr. That's 180gr in 40S&W. And 154gr in 38Spl. Personally, I pay no attention to +P loads.

 

[JDBerg]

I can only assume that +P loadings are an archaic remnant of paleoplumbic JHP designs, as +P loads from quality manufacturers often fail to meet IWBA minimum penetration criteria;

"Paleoplumbic" please explain!

 

[9x18_Walther]

"Paleoplumbic" please explain!

A convenient Google search yields this as the only webpage on the Internet to be indexed with the use of such a word.

I believe we can define it as "old lead" for the non-Latin majors in the world.

 

[MarkCO]

Coin a new word and post a chart...give that man a star.

For the OP, I generally agree with 44Amps post.

As some other discussions on TFL have adequately pointed out lately, the only set of variables that matters is the one in which you have to rely on the tool (or tools) you have chosen to effectively complete the task at hand, whatever that may be. I have done a lot of ballistics testing and performed several analysis of bullet paths inside people using virtual autopsy. Some who lived and some that did not. One thing I can say with certainty is that the parameters all matter and they can not all be controlled. Handgun cartridges are, by their very nature a compromise between a knife and a long gun...as long as we have those constraint, the arguments will continue.

Better design of bullets has brought us to a point where slow moving heavy bullets do not always perform better than faster moving lighter bullets. That has narrowed the gap between 230 grain ball at 850 and 115 JHPs at 1300. So too, the amount of improvement to be gained by 45 ball was smaller, so .45 ACP has benefited less than 9mm from the improvements in the last 20 years. The notion that "heavy for caliber" is always best no longer holds true either.

There is one set of parameters for which one caliber at a certain velocity will perform better, but that might not be your set, so choose the best based on the data.

 

[44 AMP]

In an ironic way, the very existence of 9mm +P (and +P+) affirms the ancient argument of the .45 guys, that the (original) 9mm simply wasn't quite good enough.

It is worth noting that the original 9mm Parabellum specs were a 124gr FMJ at 1050fps from the 4" Luger. Later, a bit before WW I, it was upgraded to a 115gr at 1150fps.

Today we have the 9mm 115gr at 1300fps +/- depending on the exact load. If this isn't +P compared to the original loading, what is??

And also note that throughout the same time, the .45 load of 230gr at 850 remained unchanged.

I try to ask, without bias, why the 9mm needed improvement (if it was so good to start with), and the .45 did not?

Everyone seems to agree that modern 9mm ammo (defensive JHPs) are very good, quite good enough for duty/self defense use.

That wasn't always the case. For some of us, it still isn't.

 

[jmr40]

In the USA 9mm has traditionally been downloaded. The rest of the world loads standard 9mm 124 gr loads to 1200 fps. Which is almost exactly what is typical of most 125 gr 357 mag loads from 4" or shorter barrels. In this country we call the same loads +p, or even +p+. I get 1250 fps from Speer 124 gr +p ammo and trust it as well as any handgun round.

 

[KyJim]

For the longest time, most people recommended 9mm loadings in +P, yet rarely do I see mention of +P loadings in .45 ACP.

The pressure increase between +P and the standard loading in both calibers is roughly 9%.

Momentum is more important in bullet penetration than kinetic energy. In turn, a bullet with more mass will have more momentum than a lighter bullet with the same kinetic energy as the more massive bullet. This is simplified because there are other factors involved such as the cross-sectional density of a bullet.

The heavier 230 gr bullet of a .45 acp has enough momentum to penetrate, and expand well with a decent hollow point, without the need for +P loads -- at least out of a five inch standard Government configuration. They also work do well in the 4.25 inch standard Commander configuration. When you drop below that, you may well need the extra velocity a +P loading can give you. Keep in mind, though, that not all +P loads are the same. Some will maintain near peak pressure longer or achieve it quicker than others.

On the other hand, most 9mm offerings can use the extra velocity +P gives them. You can see that the heavier loads, 124 and 147 gr loads generally perform a bit better because of their mass.

Finally, keep in mind that bullet design is important. Notice the 115 gr +P+ actually penetrates less than standard pressure loads in bare gel and denim covered gel, though that's not a perfect comparison because different test guns were used. The higher velocity may cause expansion that is too quick and/or too much, resulting in lower penetration. I also know that when a .357 magnum Gold Dot is driven to very high speeds (say, around 1,500 fps), the bullet may lose its jacket and fragment.

 

[Nick_C_S]

This is a strange thread paleoplumbic? "old lead" would have sufficed

I like the chart. Except my 3" 686 burps out the 125gn GDHP at 1297 f/s; not to mention, I find it odd that the 158 GDHP is faster than the 125's in the chart. I actually believe the 125gn data is a typo (maybe it's supposed to be 1289??). Whatever. Let me assure anybody reading this, the 125gn GDHP for 357 Mag is a beast - a very hot round. I won't carry it. Too intense for me.

For 9mm, I carry the 124gn GDHP +P. 1182 f/s through my 3.7" Kahr CW9. They're getting 1235 through a longer barrel - seems legit. I have also chronographed the non+P GDHP 124 - 1048 f/s through the Kahr. So the +P clearly has more poop than its lower pressure counterpart. I have decided that I can handle the +P's well enough to carry. But there is a clear noticeable difference between the two; as I have fired them in alternating fashion.

I recently acquired a new 1911. The plan is for it to see nightstand duty (currently, the job is being occupied by a G20 with 180 Hydra-Shok's). The 1911 is not broke in yet and I want to get more comfy shooting it; not to mention, get confident with its reliability. At any rate, I bought 5 boxes of the 200gn GDHP +P's for it. Haven't shot any yet. When I do, the chronograph will be in attendance. Hopefully, I will find the rounds' shooting characteristics (recoil, report, flash, velocity) acceptable for self-defense duty. We'll see.

The whole "+P" thing is awash in ambiguity - more so than "paleoplumbic." I don't really put much stock in the term, other than to know the manufacturer is telling me it's one of their hotter loadings. The rest is up to me to evaluate.

 

[iraiam]

The thing about this is; pretty much all defensive ammunition is designed to penetrate the same depth and expand the same percentage, a 115 gr. 9mm round is designed to penetrate to the same depth as the 230 gr. 45 ACP round. Basic physics tells us that in order for the lighter bullet to do the same job, it must have more kinetic energy imparted onto it (in the form of a higher velocity), the lighter bullet will also shed energy faster than the heavier one.

I can give a specific example, many people used to say the 147 grain HP bullet was no good for the 9mm because it would not expand, the reason they saw inferior expansion was virtually all the 147 grain ammo back then was loaded at about 950-975 fps at the top end, I still see commercial 147 grain HP ammo loaded at this velocity, why is beyond be, it's common and easy to get that weight bullet well above 1000 fps in the 9mm today, often without needing a +P charge.

I adopted the 9mm 147 grain HP 20 years ago and saw great results by loading to +P/9mm NATO pressures, this effectively eliminated the lack of expansion complaint. Even an old "inefficient" HP bullet for the 9mm will expand properly when it's fired at 1050-1100 fps.

 

[44 AMP]

virtually all the 147 grain ammo back then was loaded at about 950-975 fps at the top end, I still see commercial 147 grain HP ammo loaded at this velocity, why is beyond be,

The 147gr 9mm Parabellum load was intentionally loaded subsonic, to be the most effective round in suppressed submachine guns.

Loading the standard 115 or 124gr rounds subsonic gave inferior results, so the heavier than standard (at the time) 147 was used.

Sure, you can load it hotter, but when you do, you hit the sound barrier, which works against best suppression.

It was a specialty load that somehow got adopted for general use, and like a lot of things, when used outside of its intended niche, people complained about what it did, and didn't do.

 

[Mrgunsngear]

I'm not a fan of +p for any caliber for defensive use. Reason being, all handgun rounds are poor 'stoppers' and it's more important to get multiple hits as fast as possible and generally standard pressure will lead to that happening more consistently. Also, +P's will generally reduce penetration and I prefer the extra penetration of the standard loads. But, to each their own I suppose.

 

[Big Shrek]

.45acp +P??

Might as well go to 10mm instead.

 

[Limnophile]

A couple questions (lovely chart, btw)

A similar chart is available for Federal HST rounds:

http://www.everydaynodaysoff.com/wp...eral-Premium-Tactical-HST-Ammo-Comparison.jpg.

I think it shows similar results despite the different JHP design.

Who is IWBA? And why does their standard matter?

International Wound Ballistics Association. It was lead by retired Col. Martin Fackler, MD, who was a US Army battlefield surgeon then the director of the Army's Wound Ballistics Laboratory. His major achievements, based on human surgical and pathology evidence, included discovering the importance of bullet penetration depth, the importance of military rifle bullet fragmentation, and the developments of standardized 10% gel blocks with which to obtain comparable penetration and rifle fragmentation data.

Upon retirement Fackler formed the IWBA to influence industry and law enforcement on effective cartridge design and selection. Members included trauma surgeons, medical examiners, and law enforcement ballistics experts. The organization essentially adopted Fackler's findings from his work with the Army. Fackler helped organize and participated in the FBI's 1988 workshop on handgun wounding effectiveness at Quantico. The FBI essentially adopted the IWBA criteria with relatively minor modifications:

gundata.org/images/fbi-handgun-ballistics.pdf.

The improved effectiveness of especially today's 9 Luger JHP rounds is directly the result of law enforcement embracing the Fackler's science and demanding science-based JHP designs from ammo companies.

The IWBA dissolved not long after the Quantico workshop, its job being done.

Somewhere online (sorry, I can't find it now) is a generic IWBA ammo procurement specification meant for law enforcement agencies. While it is presented such that a given agency can fill in the blanks to tailor the spec to their needs, recommendations are provided that allow us to see the IWBA's thinking.

For example, the IWBA recommends a sample size of 10 shots to determine bullet penetration. They allow for specification of a penetration standard deviation, but state that modern quality JHPs should easily be able to attain a sample standard deviation (a measure of expansion reliability) of 0.6 inch. Given that sample standard deviation, the minimum average recommended penetration of 12.5 inches, and the statistical one-sided tolerance factor factor for 95% coverage and 95% confidence of 3.0, the IWBA's recommended average penetration means one can be confident that 95% of the rounds will penetrate bare gel at least 10.7 inches. Thus, the FBI's relaxed minimum average penetration of 12.0 inches means 95% of high quality JHPs will penetrate bare gel at least 10.2 inches. Expect penetration in the human body to be less; thus, beware shaving the recommendations too much.

Why buy more bang to get more recoil, worse accuracy, more wear and tear on your gun, and inadequate penetration?

Are you meaning to say this applies to all +P loads?? If so, I'd say there are too many variables at work to make that an accurate statement.

Given the identical JHP bullet design and construction, my generalization seems to be true.

It is an interesting chart, and I'm sure it accurately shows the results obtained from the testing, but remember, it only accurately applies to the specific loads used in the testing.

I found it interesting that the 125gr .357 bullet out penetrated the same weight bullet, at higher speeds, from both the 9mm+P and the .357 Sig, in every category, except after going through 20 gauge steel and laminated safety glass.

Both the .357 loads shown are listed at just BELOW 1200fps, and yet they have the best penetration numbers other than the hard barrier penetration categories (steel, glass), and in those groups are only beaten by a couple of loads, in other calibers (which are moving ~100-200fps FASTER.

When a 125gr .357 at 1189fps penetrates significantly more than a 125gr .355" bullet at 1235fps (9mm+P) AND a 125gr .355 bullet at 1379fps (.357 Sig), there is more at work than just bullet velocity (pressure).

Bullet construction matters. More than just a little.

I do assume bullet construction differences are responsible for the performance differences you note.

I notice that regardless of caliber rounds seem to be designed more for penetrating heavy clothing rather than bare gel. I'm guessing this is because law enforcement figures most bad guys are clothed. At lot of rounds seem to be designed to perform to the minimum penetration specs rather than the maximum specs. I'm guessing this is because of law enforcement's concern about overpenetration.

 

[Limnophile]

"Paleoplumbic" please explain!

9x18 got it right. It's a neologism that refers to the old lead culture of bullet design prior to the FBI's Quantico workshop of 1988, which changed the JHP bullet design culture for law enforcement and civilian defense.