What's the Logic behind + P ammo

[mnrivrat]

I keep seeing the references to + P ammo and the "Hot" loaded ammo like Buffalo Bore . As well as shooting heavy slugs that creat high pressure loadings.

Along with this usualy comes talk about which guns will best handle + P and heavy loads within a caliber.

Am I the only one that gets a little nausea from the thought of running + P or heavy loaded ammo from a gun designed primarily for a more standard loading ?

I am usualy thinking that if you want to shoot + P in a .38Spl , why don't you buy a .357 Mag. ?

If you want to shoot + P in a .44 Mag. why not buy a .454 C or a .460 S&W ?

Why subject your firearm to a loading that is likely to shorten it's life span and be unpleasant to shoot in a gun not realy made for the amount of power you want to subject it to ? I know that some guns are manufactured with enough extra strength to handle + P , but what is it that makes sense to those of you who use + P ? In 50 + years of shooting I never felt the need to use + P ammo in anything I have owned for any reason. Convince me there is a real benifit from + P loadings, because I don't get it .

Please spare me the I can't afford a .357 mag, so that's why I shoot + P's from my .38 Spl .

 

[HM2PAC]

My wife has a Ruger SP101 chambered in .357RM. The recoil of a full .357 RM load is too much for her to enjoy and shoot accurately. So at the range she plinks/practices with .38 Spcl, but loads and carries .38+P.

 

[jmr40]

I think your logic is wrong. I would shoot .38+P in a .357 or .44 specials loaded hot in a .44mag. This would give me a mid power load with less recoil and blast in a gun that could easily handle the power.

 

[Trisha]

mnrvrat, I love my S&W 649 far too much to load it with +P .357 ammunition. I do, however, love to follow max load data when I make handloads for the DE and Super Redhawk in .44mag - it's fun to shoot! I'll probably never hunt the local mule deer with the SR, but in this landscape, it would be well suited and the load would be very adequate.

 

[KI.W.]

I have Dan Wesson .357 Super Mag, and am reloader too. So can to have all kind loads with .357 Rem Maximum cases. Ofcourse .38spl-, .357-factory loads ok.
VihtaVuori "Tin Star"-powder(N-32C) brilliant for .38 spl-loads.

 

[19-3Ben]

Am I the only one that gets a little nausea from the thought of running + P or heavy loaded ammo from a gun designed primarily for a more standard loading ?

I think you might be. 'The way I see it, guns are designed to work within to within a certain pressure for each cartridge. So long as the pressure is within SAAMI spec, there's no reason a really good quality gun should not be able to take it without any sort of life-span-reduction. I mean, of course there will be a little more wear and tear on the gun but it ought to be insignificant. I'd follow the idea that if you can shoot enough +p to wear out the gun, you can easily afford a new gun. This is of course, only talking about good quality guns. If yu want to put tons of +p through your Charter Arms, you're gonna break it sooner or later.

As for why? Well, to get the most out of the gun. If the gun can take rounds from x all the way up to z in power, why not get as close to z for defensive purposes as possible? You can get all the possible power out of the round for when you'd really need it.

Now, when people talk about which gun can take the most +p or whatever, honestly, I think they basically are just asking which gun is strongest. I don't think many people (including myself) practice by shooting +p ammo. The only time the gun is loaded with +p is when it's carried or otherwise in a defensive role.

 

[SaxonPig]

Generic +P is standard. Starting in the 1970s the ammo companies began reducing the loads to avoid lawsuits from owners of old, cheap, imported guns that were blowing up. In the early 1970s the standard 38 Special load was a 158 grain lead bullets at 870-950 FPS depending on manufacturer. Now the standard 158 load hits a truly pathetic and wimpy 730 FPS. The +P was created to offer something more than the lawsuit-safe ammo yet give them liability cover ("We told you not to use +P"). Unfortunately, S&W and others have taken this way too far, with their lawyers convincing them to disallow +P in perfectly fine revolvers as extreme CYA tactics.

At this point someone will jump in and point out that they used to inflate the claimed velocities by using long pressure barrels for testing. Yes, but not THAT much. I have chronographed old factory ammo and 800-875 FPS can be expected. Much better than the 730 currently offered.

A typical factory +P is a 125 at 925. Well, that's not really any hotter than the old standard load. Indeed, +P is loaded to 18,500 PSI and industry allowable is 21,000 so +P is actually well under the maximum for the caliber. I suspect that those loads from the specialty ammo makers (Big Bore, etc) are right at 21,000 PSI. Still within maximum allowable but when compared to current offerings from Winchester, Remington and Federal they look really hot.

 

[Timthinker]

As I understand the matter, + P ammo for the .38 Special was designed to improve the "manstopping" performance of that round. The old .38 Special was the mainstay of most American law enforcement departments some years ago. Rather than change sidearms, departments permitted hotter loads intended to improve the ballistics of the .38. Judged from this criteria, hotter loads make sense.

Whenever someone attempts to understand an issue, they should look at the historical context into which the decision was made. This helps clearify matters. I hope this brief explanation sheds some light on the issue for you.


Timthinker

 

[spwenger]

The Logic Is

Kinetic energy = one-half mass X velocity squared.

It generally takes higher pressure to produce higher velocity.

The .38 Special cartridge was introduced in 1899, when steels were not as well made as they are now. The first version of the +P .38 Special, was introduced in 1930 and was only intended for use in S&W's larger N-frame .38/44 revolvers, specifically built to handle the higher-pressure load. Now we've got extended-J-frame revolvers built to handle .357 Magnums.

In fact, +P .38's are essentailly standard in anti-personnel loadings now, to the extent that it's quite a challenge to find a decent standard-pressure load for self-defense use.

 

[rainbowbob]

I have shot enough +P through my old Chiefs Special snub to know what it feels like - and didn't notice much difference in recoil. I practic with .38 special for the cost factor - and carry Gold Dot HPs for SD.

 

[SaxonPig]

Aw Hell, I know folks are sick of seeing it (and I have recently been accused of being repetitive but what can you do when the same questions keep being asked over and over?) but here's my 1942 M&P with 500 rounds of Remington +P (125@925) and 600 rounds of my own SD loads (125@1150) that I fired through the gun to see it would be damaged in any way after hearing all the dire warnings about +P in older guns.

It wasn't. What a shock.

 

[Jim K]

The .38 Special for many years was loaded with a 158 grain lead bullet at a pressure of about 18k psi. Today's +P loads exceed that by only about 2000 psi. They get the high velocity the old fashioned way, by reducing the bullet weight to 125, 110 or even 100 grains. Of course, you have less energy, but to advertising gurus, there is ALWAYS a free lunch.

(Note that the LE +P+ ammo has pressures in the .357 Magnum range and was supposedly to be used only in revolvers chambered for the .357.)

Jim

 

[yongxingfreesty]

hottest +p ammo i feed my j frames are golden saber +p and double tap gold dot +p. HOT!

 

[GRIZ22]

Am I the only one that gets a little nausea from the thought of running + P or heavy loaded ammo from a gun designed primarily for a more standard loading ?


No you are not. I carry standard ammo in my J frames (not 357 rated). The extra control and shorter recovery time standard ammo gives in a J frame far outweighs any advantages +P gives in a small revolver. You can find plenty of threads where the poster "shows off" his 10" 10 yard groups with hot ammo. There are also many who believe a J frame is no good past 10 yds and might shoot better with std velocity loads.

I think the extra wear +P gives on a K frame or bigger is negligible.

 

[rcmodel]

First, I agree with SaxonPig.
Todays +P .38 Specials were yesterdays standard pressure load.

But with that being said.
If you can't Get-R-Done with standard ammo in your caliber of choice,
your caliber of choice is the wrong caliber!

I would have no qualms whatsoever about carrying 158 grain +P LSW-HP loads in my old J-Frames for SD use.

But, I wouldn't put a +P+ load in them on a bet!
Only the folks who loaded it, and the folks who ordered it, have any idea what pressure it is loaded too.

rcmodel

 

[loop]

The +P designation was created because some cartridges had been around since the 1800s, but by the middle of the 20th Century machining and metallurgy allowed for much higher pressures in the same cartridges.

In order to be able to sell ammo that would function safely in say a .38 Special that was made in the 1800s the pressure would have to be low enough to not harm the gun. But, by the 1950s the same cartridge in a modern gun could handle much higher pressures.

Basically, +P means it should only be fired in modern guns. Standard pressure loads can work equally well in a 1910 9mm as in a 2008 9mm, but a +P might blow a 1910 Luger to pieces.

Manufacturers of new guns will say not to fire +P because of a lingering lack of standards for what constitutes +P. A Winchester +P may have far different standards than a Federal +P which may also vary greatly from what is listed for handloading.

Personally, I have no use for +P. If I want particular ballistics I get a gun that yields the desired ballistics.

I've never heard of any kind of Magnum +P. That may be because I don't care or pay attention to .357 or .44 anymore. It may also be because Magnum indicates a round is made to handle the maximum pressure that can be yielded by that cartridge case to begin with.

I used to load .38 Special to .357 Mag loads for my .357s. I suppose that would have made them +P. I didn't care. I made them for my .357s.

I would not hesitate to shoot +P ammo out of any modern firearm. If they could not handle it I'd consider them to be a crap gun.

 

[wristtwister]

Changes in loads and bullet shapes

I would never use a crap gun for self defense anyway, but the +p ammo in 357 and 44 magnum has an added "noise effect" when shooting. Whether or not you hit your target, it's going to make him change his underwear.

The real argument about what load to use is pretty much determined by whether or not you can stop a charging druggie with a knife in close combat. When I was an LEO, I carried a .357 with semi-wadcutters because I knew if I shot somebody with it, they were going down. They might get back up, but it's doubtful... however, I knew that .357 was going to put them on the floor.

Back then, (1970's) only the swat teams had body armor, and the rest of us depended on our guns to get the job done. I never worried that I couldn't put somebody down, and the loads were more focused on bullet type (hollow points were prohibited) than powder load. If you carried a .38, they allowed "super-vel hollow points", but anything else... no hp ammo, and the bullets had to conform to being "standard" ammunition.

WT

 

[xjchief]

I tried out some of the Federal 38 Special +P ammo in my wife's snub 38. Blindfolded I wouldn't have been able to tell you WWB from the +P.

 

[nero45acp]

"But with that being said.
If you can't Get-R-Done with standard ammo in your caliber of choice,
your caliber of choice is the wrong caliber!"


+1

If I was concerned that 9mm or .38 Special was inadequate, I'd move up to a .40 S&W or .357 Mag rather than fart around with +P.


nero

 

[ImARugerFan]

If you want to shoot + P in a .44 Mag. why not buy a .454 C or a .460 S&W ?

Because the cheapest possible ammo (for practice) is considerably more for the .454 or .460 than in the .44. I practice with cheap rounds in my .44, but plan on probably picking up some buffalo bore for hunting. (Of course i'll practice a bit with the buffalo bore too )

 

[Halo]

I like +P in 9mm because it more closely approximates the nominal loading for 9mm. "Standard pressure" 9mm ammo from Europe is noticeably hotter, and in all likelihood would be marked +P if it was manufactured here.

As far as other calibers go, I'm inclined to agree with the arguments against +P.

 

[BlindJustice]

I have a S&W Model 60 .357 Mag. 3" Bbl. I have limited it to
.38 Special +P Speer 125 gr. Gold Dot JHP &
.38 Special Hornady 125 gr. XTP JHP rated @ 1,000 FPS
Muzzle blast and recoil is about the same Seems like good
ammo for a bedside backup handgun..

I looked at the S&W Web site for all of their currrent offerings
in .38 SPecial - they are all rated for +P these days.

I also have a S&W 686P 4" Bbl. weighs in at 38 oz and
I'm still working on recoil management, what with the lightning
bolt muzzle flash and muzzle flip up There's no way my
60 at 24 oz needs to be loaded with the heavier .357 Mag loads
unless it's all I had to use.

SAAMI ratings
.45 ACP 21,000 C.U.P.
.45 Auto +P 23,000 C.U.P.
.400 CorBon 23,000 C.U.P.
I was corrected stating on a different forum about a gun writier's estimation that the .400 CorBon must be in the 26,500 C.U.P
range he said SAAMI rated it at .45 ACP +P pressure two years
ago. It would be nice if SAAMI would print their latest
it's only been 14 years I am told by someone who runs a small ammo
company.

Yes, I have a .400 COrBon barrel for my 1911, fires .40/10MM 155 gr.
bullets in the 1350 FPS range for a flatter shooting bullet at extended ranges

I picked up some interesting ammo - it's hard to find .45 ACP 200 gr. loaded factory ammo so when I found two boxes of +P 200 gr. Hornady XTP JHPs I bought them both - checking ont he web it's rated at 1,085 FPS not bad for the old Warhorse I'll see how it shoots in my 1911 as well as my S&W 625

Hey, speaking of a platform that can take +P the 625 with a 5" Bbl. at 45 oz and most of it's large N-Frame brothers with the monicker Magnum on their chamberings - +P pressure is not an issue. Pssst, SAAMI rates the .45 Auto RIm at 14,000 C.U.P. - this is the same as cartridges that were originally used in older 19th century handguns like the .38-40, .44-40, .44 SPecial .45 Colt, It's silly to rate the Auto Rim with the same case diementions as a .45 ACP case but with an extra thick rim/base - it's .00810 thick in comparison a .45 Colt rim is 0.00610 I have some .45 Auto Rim that delivers
225 gr. SWCs at 925 FPS extracts easily as well as .45 ACP 185 gr.
Golden Saber @ 1,050 fps same maker offers it in +P at 1,100 FPS
for the extra 50 FPS they can keep em.

There's no current +P ranking for the old .45 Colt hot loads but most manufacuters put out a warning for these to only be used in Ruger SAs or
THompson Center Contenders

The Pre-WWI and PRe +P rating .38 SPecial that was used only for a few
years before the advent of the .357 Magnum was called .38 High Velocity
and only recommended for the N frame Smith & Wesson revolver - Colt got out of the big frame DA revolvers at the end of WWI.

 

[tipoc]

Officially SAMMI only recognizes the .38 Spl. +P and the 9mm+P (and +P+). No other rounds are actually +P. +P ammo is within SAMMI specs and for the reasons given by others already, is labeled as such by ammo manufacturers. SAMMI does recognize that .38 Super is also known as .38 Super +P but that is only a way of differentiating the .38 Super from the old 38acp. Usually it does not mean higher pressures with the .38 Super.

Some manufacturers, to promote sales, refer to some of there products as +P. They are usually just heavy loads though and within SAMMI specs though.
They are usually labeled as such as a way of letting folks know that they are best used in only certain guns. A 250 gr. pill in .45 Colt at 1200 fps will wear out a Colt SAA but will work fine in the Ruger Blackhawk. The +P label on the box of .45 Colt is there to let folks know this, a warning of sorts. But officially there is no +P .45 Colt or +P .357 or .44 Magnum, just hotter loads.

.38 Spl. +P is still a lower velocity round with a 158 gr. pill than the old 38/44 load. It may get you around 900 fps with a 4" barrel. It is fairly mild even out of a steel J frame with just a little pop from a lightweight.

9mm+P is a bit hotter than standard but most modern 9mms are built to take that and more. The old Luger was built around the 9mm that was hotter than todays standard U.S. 9mm.

The logic of +P is to get a bit more punch from the round than standard ammo in a self defense situation. Fit the ammo to the gun and the gun and ammo to the task.

tipoc

 

[BlindJustice]

Re-read my post
RIm thickness
.45 AUto Rim = 0.0910 inches
.45 Colt = 0.0610 inches

In 1920 the .45 Auto RIm was designed to duplicate the .45 ACP both
loaded with modern smokelss powders - and the guns they have been chamberd in are the N-frame S&Ws. SAAMI = 14000 CUPS is insane.imho

ok, back to +P there is no +P added to any cartridge that is a Magnum

PERIOD

I broke in a CZ 75B last saturday I fired 100 rds of WWB 115 FMJ and a box of CCI Blazer brass case 115 FMJ - then I did 10 rds of CCI
Speer 124 gr. +P Gold DOt JHPs - not very much difference in these 9MM rounds where the starting point is already in the 35,000 CUP range I've read that the Browning High Power - at least the older ones
pre-1960 before the external extractor was added should not be fired
with +P or it will break the extractor - that was some guy quoting Bill
Laverty of Cyllinder & Slide who certainly knows the BHP.

I mentioned .400 COrBon for extended ranges and flatter shooting I'd still
want the .45 ACP for HD/SD use.

 

[Srigs]

Very simple Mass x Velocity squared.

It should be +V would be more correct because more pressure = more velocity.