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+P 40 S&W loads?
5mmgunguy
Member Posts: 3,853
Are there SAAMI standards for +P in 40 S&W loads?
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Past the 45acp+P and the 357+P.
Psi ratings don't tell the whole story...
Look at the lowly .22LR...24,000psi.
Higher than the .38 special.
http://www.lasc.us/SAAMIMaxPressure.htm
.38 Special
9mm Parabellum
.45 ACP
and ALL .38 Super loads are considered +P. Are there other cartridges LABELED as "+P" ? Sure are. But there is no official standard for any other cartridges. There is also no SAAMI spec for any +P+ cartridge.
[:)]
357 magnum is *also* 35000 PSI, and so is 9mm luger. These are the same. 9mm luger +P is 38500 PSI.
41 Action express, which is a sort of "precursor" to a .40SW using a 40 caliber cartridge with a rebated 9mm rim *also* has a max SAAMI pressure spec of 35000 PSI.
Yes, "in theory" there is no reason why someone couldn't come up with a "+P" 40SW that operated at a max pressure of 38500 PSI (ie 10% higher than .40SW).
But in practice that cartridge already DOES exist; its just called the 10mm auto! 10mm uses the same bullet as a 40SW, but in a slightly longer cartridge and operates at a max of 37500 PSI! (From what I gather, real world operating pressure of most 40SW rounds is 33k psi).
Also as a matter of practice, 40SW was purpose-designed as a gimped 10mm auto, because the true "40SW +P" (ie 10mm) offered too much recoil for most police shooters, and was too harsh on guns. There isn't reason to go with something more than 40SW, when experience shows that 40SW is about the maximum that most shooters want to shoot for "service" use. As a matter of fact, a lot of shooters with 40SW guns like "reduced recoil" loads, that basically replicate 9mm+P ballistics. IE, there is more demand for LOWER power 40SW rounds than higher!
As it is now 40SW cartridges are already pushed near max pressure capacity with standard loads. That's why most of the "kabooms" are with .40SW. . .the cartridges themselves offer less margin for error than others. Pushing the brass past its current max isn't wise. . .as above the "standard" 40SW is basically a "+P" already.
Bottom line, if 40SW isn't enough for you, go get a 10mm.
On .22LR, 38 special, and 45ACP, those are all effectively black powder era cartridges, explaining the relatively low operating pressures. (45 ACP was designed specifically to emulate 45LC revolver ballistics in a semi-auto platform). .22LR is both a rifle cartridge, and a narrow-diameter one, explaining the higher operating pressure, compared to the other pistol ones.
Never did get what some people thought about the +P or +P+ 40's when there's the 10MM. Also that .40 Super. Ain't that just a 10MM?
Well, in theory the "advantage" of a 40+P (vs 10mm) is that you've already got a .40SW gun that will run ordinary 40SW ammo. So you could get the ballistics of a 10mm if you wanted to without having to buy a separate 10mm gun.
In practice, +P loads exist as modern ballistic improvements for 100 year old cartridges (eg 38 special, 9mm, etc), because both brass and guns have improved in that time. The 40SW is already "improved" by having been designed relatively recently for modern pistols. The SAAMI max working pressure ALREADY represents the max safe pressure for many platforms (or perhaps more than the safe pressure, see below).
If you look at the Buffalo Bore 40sw+P, they advise explicitly against firing it in Glocks for risk of case rupture ("Kaboom").
quote:Owner of Buffalo Bore Tim Sundles on Buffalo Bore Heavy 40 S&W +P Ammunition:
There is such a variety of 40 S&W pistols in public use that we will not determine what pistols are compatible with which 40 S&W +P loads - this is your responsibility! We will add that this ammo is safe in pistols that use a fully supported chamber. Please read the safety notices below. The first one is taken form the Speer #13 loading manual. The second is taken from Hodgdons #27 loading manual.
SAFETY NOTICE
"Some pistols chambered for the 40 S&W cartridge may not provide complete support of the case head. If this condition exists, normal pressure loads such as those shown here can cause the case wall to bulge or rupture at the unsupported point. Contact your firearm manufacturer to determine if your pistol completely supports the case head, or ask a gunsmith to inspect your pistol before using it with ANY ammunition. It is the gun owners responsibility to know his firearm and its capabilities and limitations."
40 S&W WARNING
"This data is intended for use in firearms which fully support the cartridge in the chamber. Use of this data in firearms which do not fully support the cartridge may result in bulged cases, ruptured cases, case head separation, or other conditions which may result in damage to the firearm and/or result in injury or death of the shooter or bystanders."
Glock happens to chamber their 40 S&W pistols without a fully supported chamber and both of those above safety notices are likely aimed at Glock. I know of no other 40 S&W handguns being sold in the US that don't have fully supported chambers. If you really want to shoot our 40S&W ammo in your Glock, have an after market barrel that uses a supported chamber, dropped into it. This is a fairly common practice and will give you the safety margin needed to fire our ammo in your Glock. It will also likely give you more velocity than the factory Glock barrel. I personally own two Glock Model 23's. Both of mine are going to get after market barrels dropped in so that I can use this excellent ammo in them. The issue of Glock pistols not having a fully supported chamber is with the 40 S&W cartridge only, not 45 acp, 10mm, 9mm or 380 auto. While Glocks chambers are not fully supported in any of those calibers, only the 40 S&W brass is weak enough in the web for it to be a safety issue. I REPEAT, only the 40 S&W is a safety issue with chambers that are not fully supported. You do not need to be concerned with this issue when using our 45acp+, 10mm, 380 auto+P or 9mm+P or +P+ ammunition in Glock pistols.
I don't agree with it, but that is what they said.
This thread brings up a good point. All the rounds and reasons Beantown gave is why the FBI came out last month and flatly stated the best round is the 9mm for people who carry service weapons. This is an across the board generality. But, their study showed too many shooters flinched with recoil. And, too many service firearms were wearing out or breaking too soon.
I don't agree with it, but that is what they said.
To be clear, the FBI has a pretty lengthy explanation about why they think 9mm is the best service round, and its based on quite a bit of research and experience. For those who haven't seen it, you can see a good summary here:
http://concealednation.org/2014/10/fbi-decides-on-9mm-as-their-1-choice-and-have-tons-of-science-behind-their-decision/
In a nutshell, they've found similar or BETTER performance with premium 9mm vs .40SW or 45ACP in their ballistic models, and no difference in stopping ability between 9mm and other rounds in the real world, and (tending to validate the models).
Meanwhile police hit MORE often with 9mm (which is significant when police miss the target something like 70-80% of the time they fire their weapons!), and get out shots faster. 9mms offer higher capacity and lower per-round cost.
Note that there is a difference between what is right for a police DEPARTMENT, and what is right for an INDIVIDUAL.
IE, if you're an experienced and skilled shooter, aren't restricted to carrying a "service" type gun (but something else), can afford more expensive ammo, etc, then other caliber choices may offer advantages.
Police DEPARTMENTS have to offer the round that works best for a majority of its members (who may not be accomplished handgunners, of small stature, female, etc). Budget concerns matter, and so does liability.
...the FBI has a pretty lengthy explanation about why they think 9mm is the best service round, and its based on quite a bit of research and experience.
...police hit MORE often with 9mm (which is significant when police miss the target something like 70-80% of the time they fire their weapons!), and get out shots faster.Based upon my more than a few decades of experience, I'm not a strong devotee of the FBI's statistical data on LE shootings.
Over those years I've been in a position to be aware of other LEO's situations as well as my own and have never seen such highly detailed data routinely submitted to the FBI by local LE agencies. Despite what many seem to believe, there's actually no sort of required reporting to the feds every time an officer/deputy/trooper involved shooting occurs.
Contrary to how many view it, what you're seeing from them is an incomplete sampling of incidents, not full and complete info with a chips-fall-where-they-may result. This leaves quite a bit of room for admin and bean counter's wants and wishes to worm their way into the process - which is a constant battle when you're talking firearms and ammunition.
Due to this, I don't put much more stock in the FBI's 'fantastic science' than what's in the latest issue of Guns&BS. Some they offer is useful, but don't drink the Kool-Aid.