Any Reason for +P Ammo

[44MAG#1]

Is there any reason for +P Ammo other than for sales boost?
If standard gets 800 FPS and +P gets 875 FPS is it really a help? Maybe just a mental help????

[Winger Ed.]

It gets a little boost in speed and the added pressure that comes with it.
There are warnings on some, especially smaller/lighter .38s that strongly advise against using it.

Back in my revolver days, I'd load them accordingly when I had +P brass to feed my S&W 586.
They get you somewhere between .38Spec and .357Mag.

[M-Tecs]

Maybe. History is a very good teacher. In the late 1800's cartridges like the 450 Adams and the 38 Long Colt were adopted by the British and US militaries. One was 45 Cal and the other 38 Cal but they both had velocities in the high 600's to low 700's. Actual combat usage proved them to be "anemic" at best. Same for the other cartridges of the time that were under 750 fps.

In the 1970's and early 1980's the 357 with 125 grain bullets developed an almost legendary reputation for effectively stopping the bad guys.

In more recent times New York City or transit police required a 38 Special load that earned the well-deserved reputation as the "Widow Maker" for its lack of stopping power. I don't remember if it was a 158 grain LRN or a 200 grain LRN.

The unanswerable question is what point does the load becomes "anemic"?

Personally I want a 900 fps minimum.

[HumptyDumpty]

Which round are you referring to? Seventy-five fps doesn't sound like enough of a difference to even qualify as plus-p. Additionally, not all cartridges actually have a an official plus-p specification. That is, an organization like SAAMI hasn't accepted and published any sort of plus-p pressure limit. So it can just be marketing hype, but the load may exceed what is considered "normal" among manufacturers, or even the SAAMI/CIP pressure specifications. Whether or not all this is worthwhile is difficult to say; do you need a heavy-for-caliber bullet, with minimal velocity loss? Are you concerned about proper expansion of your hollow or soft points at current velocities? There is no universal answer. I shoot a great deal of 45 Auto, and found myself desiring to push its' performance envelope. Plus-p only got me an extra 2kpsi to play with, so I upgraded to 45 Super, while modifying the gun in such a manner as to technically be capable of handling 460 Rowland. I've accomplished what I wanted at somewhere around an estimated 30k psi, which would qualify as plus-p for 45 Super, though no such standard exists. Meanwhile, I am far below the 460 Rowland's pressure limit of 40k psi. If those kinds of project appeal to you, then loading to plus-p specs (or buying plus-p ammo) may be the right thing to do.

[44MAG#1]

Before this goes oblique. I am talking about +P in a given cartridge. Such as the 38 Special, 9MM, 45 Auto etc. Not using a new cartridge running at much higher pressure being called +P. I am aware that the 357 Mag is +P compared to the 38 Special but that IS NOT what I am referring to.

[Soundguy]

I, for whatever reason, have about 10x the 38 brass vs my 357 brass. I will often load up 38+p for my 357's. It's less stress than a full 357..but more umph than the stock 38.

[HumptyDumpty]

I, for whatever reason, have about 10x the 38 brass vs my 357 brass. I will often load up 38+p for my 357's. It's less stress than a full 357..but more umph than the stock 38.

I'm in a similar situation with 327 Federal. I've found that most of what I want can be accomplished with 32 S&W Long, or 32 H&R brass.

[Larry Gibson]

Apparently, from recent chronograph postings, the velocity of 38 SPL +P has been "dumbed down". Back in the mid '70s when the PD I was with went to the "FBI load" by Winchester it was touted as giving 100 fp more in a 4" barrel 38 SPL revolver. Sure enough, that's what it did running 930 fps out of the 4" M15s we carried and 950 fps out of my 5" M15 (my previous service revolver). The photo is a box of that original issue ammunition. I have pressure tested that ammunition on several occasions and it consistently gives 18,000 psi +/-. Most standard factory 158 LRN or SWC run 800 - 820 fps out of 4" barreled 38 SPL revolvers and run 14 - 16,000 psi. My own "+P" 38 SPL duplication load I use in my 5" M15 and 2 1/5" M19 is a soft cast (40-1 alloy) 358156 HP over 5.5 gr Unique. It runs 1015 fps at 20,000 psi which is the SAAMI MAP for the 38 SPL +P cartridge.

The reason for +P ammunition is supposed to be increased velocity and enhanced terminal effectiveness.

[BLAHUT]

what are you trying to accomplish with the round? just speed ? accuracy ? stopping power ? target? competition ? hunting ?
for accuracy you would need to try 1/10 gr increment's to find the best load? lube ? reg primer? mag primer? your gun will tell you what it likes?
a lot depends on the bullet ?

[35remington]

Save with jacketed bullets I see no great need for Plus P in 38 as I get 910 fps with 158 grain lead bullet handloads of standard pressure. This in a four inch and 810 fps in 1.875” aluminum snubbies. This will do what I need and it meets the threshold of what I consider service level pistol capability.

[pettypace]

Maybe. History is a very good teacher. In the late 1800's cartridges like the 450 Adams and the 38 Long Colt were adopted by the British and US militaries. One was 45 Cal and the other 38 Cal but they both had velocities in the high 600's to low 700's. Actual combat usage proved them to be "anemic" at best. Same for the other cartridges of the time that were under 750 fps.

In the 1970's and early 1980's the 357 with 125 grain bullets developed an almost legendary reputation for effectively stopping the bad guys.

In more recent times New York City or transit police required a 38 Special load that earned the well-deserved reputation as the "Widow Maker" for its lack of stopping power. I don't remember if it was a 158 grain LRN or a 200 grain LRN.

The unanswerable question is what point does the load becomes "anemic"?

Personally I want a 900 fps minimum.

A shooting buddy has a nice Webley Municipal Police model chambered in .450 Adams:



Last year we worked up a self-defense load for that sad, stubby, "anemic" little cartridge. We settled on Mihec's 225 grain HBWC "manstopper" bullet at just over 600 f/s. That load had more than enough penetration to keep the FBI happy and here's how it stacks up against some benchmark loads in terms of MacPherson wound mass:



With the right bullet, the .450 Adams has more penetration and about the same MacPherson wound mass as the classic "FBI Load." It's no .357 Magnum. But I wouldn't call it "anemic."

[Savvy Jack]

Do you see +P ammunition being used in anything but hollow points or SWC's?

Once upon a time it was meant to add terminal performance, as Larry mentioned. Now days it seems to be nothing more than a promotional gimmick!

Velocity is needed for a specific hollowpoint design to expand as designed...which seems to be where the +P comes from with smaller caliber HP's

Back in the day it was said that a 45 Colt needed 700fps to fully pernitrate the broadside of a horse. Using soft lead, this .45 cal will mushroom like a hollowpoint.

[44MAG#1]

My revelation came after I downloaded VIRGEL. While giving close scrutiny to it and its ability to tell me what I could do with various calibers and bullet weights and types I was amazed to see that once a certain velocity was reached going over it even
in a great amount did not increase Defense Wound Mass.
Here are some photos which when viewed one will see the bullet weight, velocity, bullet style and Defense Wound Mass.
These are based all on a 35 caliber bullet or as input 35/100.
I used Mushroom MSH and Semi Wadcutter SWC as inputs and 125 grain and 158 grain bullets.

1 4


2 5

3 6

[pettypace]

My revelation came after I downloaded VIRGEL. While giving close scrutiny to it and its ability to tell me what I could do with various calibers and bullet weights and types I was amazed to see that once a certain velocity was reached going over it even
in a great amount did not increase Defense Wound Mass.

VIRGEL calculates "Defense Wound Mass" as recommended by Duncan MacPherson in his book Bullet Penetration: Modeling the Dynamics & the Incapacitation Resulting from Wound Trauma. Simply stated, the calculation ignores the last 3" of any penetration (where the bullet is judged to be going too slow to do full damage) and it ignores any penetration over 15" (where the the bullet is assumed to have already exited the target). VIRGEL also calculates "Big Game Wound Mass" for the entire penetration path.

We could argue about whether we should or shouldn't count the last 3" of wound mass or whether we should stop counting wound mass after 15" or, say, 18" of bullet penetration. But I figure if we're arguing over how much wound mass to count we're way ahead of arguing over velocity or energy or bullet weight or caliber.

[44MAG#1]

VIRGEL calculates "Defense Wound Mass" as recommended by Duncan MacPherson in his book Bullet Penetration: Modeling the Dynamics & the Incapacitation Resulting from Wound Trauma. Simply stated, the calculation ignores the last 3" of any penetration (where the bullet is judged to be going too slow to do full damage) and it ignores any penetration over 15" (where the the bullet is assumed to have already exited the target). VIRGEL also calculates "Big Game Wound Mass" for the entire penetration path.

We could argue about whether we should or shouldn't count the last 3" of wound mass or whether we should stop counting wound mass after 15" or, say, 18" of bullet penetration. But I figure if we're arguing over how much wound mass to count we're way ahead of arguing over velocity or energy or bullet weight or caliber.

Now keep in mind my knowledge level is very low compared to most shooters and experimenters so please keep that in mind.
I always thought that the Quicker (harder) a bullet such as a Mushrooming bullet hit a given medium the quicker and the more violent it expands. So shouldn't the Defense Wound Channel start sooner and be larger the higher the velocity just due to the quicker and larger expanded diameter of the bullet in the Defense Wound Channel even disregarding the last 3 inches?
Keep in mind I am not taking about some extremely fragile bullet that could explode and give only a surface would but a good designed bullet.
Do others see what I am missing? If you do, keeping in mind my mind, what is it.
I have tried it with other calibers too and they parallel each other.

[cainttype]

It’s obvious that “VIRGEL” limits Defensive Wound Mass calculations by penetration. The larger differences in calculations for “Big Game Wound Mass” show a full wound track potential including the extra penetration.
That it disregards the last 3” in DWM is good info… Thanks, pettypace, for clearing that up.

It seems like the calculations don’t differentiate between the wound track beginning with HPs, which in reality with HPs that work as intended isn’t too hard to overlook because they do begin to open almost immediately as target medium is impacted….

Seeing “VIRGEL” as a fairly straightforward, simple calculator I don’t expect it should/can nuance all the minutia that people might ponder.

Lastly, the “violent expansion” idea seems to focus somewhat on the “Temporary Cavity”.
At typical handgun impact velocities that temporary cavity has practically no real value, but at higher rifle speeds the cavitation effect of projectiles would be drastic.
Low speed loads with “VIRGEL” should reflect the actual tissue “crushed” by the projectile to accurate predict wound channel volume.

[44MAG#1]

So as it has been explained any velocity over the bottom line is a waste in Self Defense situations.
In VIRGEL with a 158 grain Mushroom bullet a velocity of 403 fps still gives the same Defense Wound Mass DWM as the velocity of over 1500 fps. So as long as we push the 158 grain over that bare minimum we should be okay in a defensive situation which should be quite, low recoiling and fast back on target type of load.

[cainttype]

So as it has been explained any velocity over the bottom line is a waste in Self Defense situations.
In VIRGEL with a 158 grain Mushroom bullet a velocity of 403 fps still gives the same Defense Wound Mass DWM as the velocity of over 1500 fps. So as long as we push the 158 grain over that bare minimum we should be okay in a defensive situation which should be quite, low recoiling and fast back on target type of load.

Not at all…. I’m just saying how I see this “VIRGEL” calculator reach it’s answers. It’s obviously NOT a program that was designed to deal with an abundance of variables.
Disregarding the last 3” of penetration is nothing I’d agree with, especially if I broke the spine in the last 2”, for instance.
All the various formulas have weak spots because they don’t deal well with multiple variables…. You decide what’s important, and you go with what makes you comfortable.

[pettypace]

Now keep in mind my knowledge level is very low compared to most shooters and experimenters so please keep that in mind.
I always thought that the Quicker (harder) a bullet such as a Mushrooming bullet hit a given medium the quicker and the more violent it expands. So shouldn't the Defense Wound Channel start sooner and be larger the higher the velocity just due to the quicker and larger expanded diameter of the bullet in the Defense Wound Channel even disregarding the last 3 inches?
Keep in mind I am not taking about some extremely fragile bullet that could explode and give only a surface would but a good designed bullet.
Do others see what I am missing? If you do, keeping in mind my mind, what is it.
I have tried it with other calibers too and they parallel each other.

I'm not sure I understand what you're getting at. Maybe reference to a diagram would help. Here's Fackler's "wound profile" for the classic "FBI Load."



For "Defense Wound Mass" VIRGEL simply calculates the volume of the "Permanent Cavity" using the length of the penetration path (minus the last 3") and the expanded diameter of the bullet and then multiplies by the density of tissue and also by a "nose factor" that depends on the shape of the bullet.

[44MAG#1]

Not at all…. I’m just saying how I see this “VIRGEL” calculator reach it’s answers. It’s obviously NOT a program that was designed to deal with an abundance of variables.
Disregarding the last 3” of penetration is nothing I’d agree with, especially if I broke the spine in the last 2”, for instance.
All the various formulas have weak spots because they don’t deal well with multiple variables…. You decide what’s important, and you go with what makes you comfortable.

Keeping in mind my mind.
That is a good answer. I am just trying to see how that going from just over 400 fps to over 1500 fps still gives the same DWM.
AND I guess it shows no Meplat unless it is wadcutter is not much better than a Round Nose.
So anything between Round Nose and Wadcutter is really neigh on not worthwhile
Whether it be a .200 Meplat or a .340 Meplat and those in-between.