9mm +p ammunition

Purchased a new M&P 9 back in January. I have only used 115G target ammunition with no problems. Does anyone recommend using 124G +P SD ammunition in this pistol? The dealer I purchased the pistol recommended the Winchester PDXI +P even though the S&W manual states no.

Isn't the S&W M&P9 able to fire NATO, spec 9mm?? That stuff is +P+. Glocks, Beretta, Sig, all will handle NATO spec 9mm, I cannot imagine Smith building a pistol, calling it a Military & Police and not making it able to handle the +P+ loads that the military and many police departments shoot. If it will handle NATO spec, it will certainly safely handle +P.

I was wondering the same thing. Hopefully someone will chime in with some good facts.

Jason

It will handle it. I shoot gold dot 124 +p in mine. I believe the manual says +p+ ammo may increase wear on your firearm. I don’t believe it says you can't shoot it. I could be wrong but I believe it says something to that nature.

Taken from the manual:

“Plus-P” (+P) ammunition generates pressures in excess of the
pressures associated with standard ammunition. Such pressures
may affect the wear characteristics or exceed the margin of safety
built into some revolvers and could therefore be DANGEROUS.
This ammunition should not be used in Smith & Wesson
medium (K frame) revolvers manufactured prior to 1958. Such
pre-1958 medium (K-frame) revolvers can be identified by the
absence of a model number stamped inside the yoke cut of the
frame (i.e., the area of the frame exposed when the cylinder is
in the open position).
“Plus-P-Plus (+P+) ammunition must not be used in Smith &
Wesson firearms. This marking on the ammunition designates
that it exceeds established industry standards, but the designation
does not represent defined pressure limits and therefore such
ammunition may vary significantly as to the pressures generated.
Some brands of ammunition may cause difficulty in extracting
spent cartridge cases from the cylinder or chamber. If this
situation occurs, thoroughly clean the cylinder charge holes or
chamber with solvent. If this condition persists, we recommend
changing to another brand of ammunition.

based on my observations of the 5900 series 9mm a 'carry load' of +P ammo may be actually preferred to the std factory 124gr.
try the Speer 'gold dot' 124 gr +P 'swat team' load for functioning at the range when you're comparing 'premium' loads. expensive though. and if you find they do well you may as well go ahead and order spare recoil springs maybe 2-3 lbs over factory spec.
Rem makes their Gloden Sabre in +P too.

What S&W Factory says about +P ammo

Here is exactly what the S&W manual for M&P pistols says:

“Plus-P” (+P) ammunition generates pressures in excess of the
pressures associated with standard ammunition. Such pressures
may affect the wear characteristics or exceed the margin of safety.
Use of “Plus-P” ammunition may result in the need for more
frequent service.
“Plus-P-Plus” (+P+) ammunition must not be used in Smith &
Wesson firearms. This marking on the ammunition designates that
it exceeds established industry standards, but the designation
does not represent defined pressure limits and therefore such
ammunition may vary significantly as to the pressures generated
and could be DANGEROUS.

Whatever ammo you select, the more powerful it is, the more rapid the wear on the gun will be. Evey shot shortens a gun's service interval. How much depends on the ammo.

They really don't want to have +P+ stuff in their guns. And it makes sense. There are no established SAAMI standards for the mythical +P+ stuff so how could any manufacturer approve its use?

gunslyngr

I've fired about 1500 rnds of plus p through my m&p with no obvious problems. I do recommend a stronger spring rate though.

SAAMI Specs for 9mm are:

Standard Pressure: 35,000psi
NATO: 36,500psi
+P: 38,000
+P+: Not recognized or regulated

9mm NATO is "slightly warm" but certainly not +P+ or even +P. At times NATO Spec 9mm is confused with some of the various military subgun and carbine 9mm which is screaming hot. The M&P pistols will do just fine with 9mm +P as it is a recognized loading by SAAMI. Bill

I think the current service pistols thrive on hotter ammo, whether it is +P or +P+. I have not had any issues whatsoever with either +P or +P+ in any Glock or M&P pistol.

I have never understood the allure of using +p or +p+ ammo. If you have any doubt about the safety of it, I would stay away from it. & why would someone want to take the chance of prematurely aging a fine m&p? I must be getting old. I just don't get it.

Justin69 said:

I have never understood the allure of using +p or +p+ ammo. If you have any doubt about the safety of it, I would stay away from it. & why would someone want to take the chance of prematurely aging a fine m&p? I must be getting old. I just don't get it.

Click to expand...

I might as well add my 2c even though no one seems to notice that this is a 3 year old thread that got bumped.

+P ammo makes a lot of sense for a lot of reasons. In terms of the M&P, it was actually designed to fire 40 S&W. The 9mm versions are more than capable of handling the slightly higher pressure +P ammunition. The PSI figures have already been posted but, +P ammunition is around 10% hotter than "standard pressure" ammo. We aren't talking about major differences here. I think most guys see +P on the box and assume some kind of nuclear concoction of lead/copper/sudden death.

+P allows defensive ammo to perform better in short barrel guns. This is especially important because all of today's hollow points have to reach a "critical escape velocity" to perform well. Most guys will take their favorite hollow point that performed well in a 4 inch barrel, stoke it up in their 3 inch barreled 9mm Shield, and just assume all is well. Not so. That 3 inch barrel will barely generate enough velocity to allow the bullet to perform adequately. A +P round allows the bullet to achieve that sweet spot in velocity and perform as intended even when fired from a shorter barrel.

It's also a fact that most guys are pushing it if they can get 1000rds a year through their gun. A couple boxes of +P here and there to test functionality will do nothing to "wear" the firearm in any measurable way. We would need to feed it a steady diet of +P many thousands of rounds over to even start to see the difference between +P and standard pressure. It's more internet hype and myth than actual consequence.

Now if you want to talk +P+, that's a totally different ball game. As another poster has already alluded, +P+ isn't standardized and can indeed be much hotter than what would be considered "safe". However, for a well designed, brand name gun like the M&P, +P is a complete non-issue. For those carrying shorter barrel variants (9c, M&P Shield, etc.) I wouldn't carry anything but +P ammo.

I wouldn't go so far as to say it's irresponsible to carry non +P ammo in the shorter barreled guns but, it's certainly sub optimal and I think most people are oblivious to this. The ammo industry could do a better job explaining that all these ccw friendly pistols also fall out of the operational design parameters of most standard pressure hollow points. And so, that is one reason why it's actually preferred to use +P ammunition.

Justin69 said:

I have never understood the allure of using +p or +p+ ammo. If you have any doubt about the safety of it, I would stay away from it. & why would someone want to take the chance of prematurely aging a fine m&p? I must be getting old. I just don't get it.

Click to expand...

I GET it......it falls in the realm that more and or bigger is better.......I bet you're not too old to understand that....but I figure I don't need hot loads to punch holes in paper

My SD ammo is Corbon DPX 115 +p. No problem or problems... (it's hot... just like my wife )

Curiously my load of choice is the Speer 124gr. Gold Dot+P in my 9mm handguns. This is the load of choice of the NYPD.
But I have used and notice that the 147gr JHP is the current load of choice of the FBI, and DPS.
Noted competition shooter Todd G. Took an M&P9 FS to 67,000 rounds sand shot the above load in the program along with others.
If I decided tomorrow to change loads it'd be the 147gr. Federal HST standard pressure.
+P+ was an attempt to get .357 Magnum ballistics outta the 9mm, if you want that then get a .357 SIG chambered pistol or the Magnum!
9mm works ya just gotta practice.
Dale

Just some food for thought. Above all, use what you believe in and have confidence with. The engineers at the Federal Cartridge Company and Winchester LE Divisions recommend a 147gr 9mm loading out of short barrel 9mms. Bullets such as the 147gr Federal HST and Winchester Ranger T are not velocity dependent to perform and they expand over a wide range of velocity out of any barrel length. The +P loadings require more barrel length to completely burn their powder and get up to speed. Often their hollow point designs have a narrower window of expansion and are more velocity dependent to expand. +P loadings in short barrels may not have enough dwell time to reach full potential. A heavy bullet out of a short barrel will loose the least amount of velocity. In any barrel length 9mm I carry for serious business it is loaded with the standard pressure 147gr Federal HST. Bill

We cover this in the reloading section a lot. The barrel being too short to fully burn powder isn't really an issue. For instance, a slow burning powder in a 6 inch barrel loaded to magnum pressures will still also be the fastest when fired from a 2 inch barrel. So if we fire +P from a 4 inch barrel, it will be faster than if the same bullet is fired from a 3 inch barrel. However, +P fired from a 3 inch barrel will be much closer to a standard pressure round fired from a 4 inch barrel. The goal is to get close to that velocity spread of a service-length handgun barrel to allow the ammunition to perform as designed.

Check out the ammo tests from TNoutdoors9, PockGunsandGear, and Shootingthebull410 (all have youtube channels). The +P ammunition consistently performs better out of short barrels, especially firearms with barrels under 3.5 inches.

Speer is the only company I am aware of that specifically produces bullets designed for short barrels. All the other guys (winchester, federal, remington, hornady) just use the same bullet design for standard and +P. In order to get that bullet design to open up, it has to be driven faster to get back into the sweet spot when fired from a short barrel.

The only exception to this rule is the Winchester Ranger +P+ loading. These are still designed to be fired from service-length pistol barrels and will not reliably expand when fired from short barrels, even though it is +P+. This is entirely due to bullet design and less a function of velocity. Besides this one round, the HSTs, Gold Dots, PDX1s, Golden Sabers, Hydra Shoks, Critical Duty, and many other rounds will perform most reliably from a short barrel at +P loadings.

I agree that using a heavy-for-caliber bullet can be a good strategy for short barrel defense pistols. However, I encourage you to watch some of the ammo tests, they might surprise you. Many standard pressure, highly respected rounds fail to expand when fired through 4 layers of denim in a 3 inch barrel. If we take the same round and the same gun, and just fire it at +P velocities, it gets back into the performance window that it was intended for.

It's also worth noting that often times, firing +P ammunition from a service length barrel will result in LESS penetration because the bullet is now starting to be over driven and will expand much faster. It will dump more energy in a shorter track of penetration. So there's always this compromise of trying to find enough expansion, and enough penetration. Usually if we have too much of one, we don't get enough of the other. But now this is starting to stray off topic. As you can probably tell, this is of great interest to me and it can be quite interesting to follow because the results aren't always what we would expect to see.

Here's a very recent test comparing +P 124grn gold dots out of a 3 inch barrel. He also references another test where he used standard pressure gold dots of the same weight. The difference in performance is dramatic. He has also tested some heavy-for-caliber 9mm ammunition as well.
Ammo Quest 9mm: Gold Dot 124-grain +P, regular vs. short barrel in ballistic gel - YouTube

The main thing that I've learned is to not adopt the old adage "if the police use it, it must be good". Law enforcement agencies are only interested in what will perform out of their issued firearms, which rarely match up to the smaller, more compromised guns that most of us will carry. As a result, it's a bit of a false pretense to just base the performance of ammunition on the narrow focus that law enforcement agencies place on it with their service weapons. It's also worth noting that when short barrels are allowed in a law enforcement setting (off duty carry, backup carry), one of the most recommended rounds for revolvers is actually the Speer Short Barrel +P loading. In my opinion, this is an endorsement from law enforcement agencies all but admitting their service length high performance bullets don't deliver the goods out of a short barrel unless driven back into that velocity sweet spot. And even then, they still recommend a bullet design for short barrels, the Gold Dot 135grn, that will allow it to open at lower velocities (lighter bullet, bigger cavity, softer lead core).

I just picked up a Shield in 9MM and had the same questions so I asked S & W directly. The response, "You can use +P ammunition, but using +P+ ammunition will void the warranty".

Seems Speer Gold Dot 9MM +P short barrel is not to be found so I had an extensive discussion with Corbon. They have tested their SD ammo in 3" and longer barrels. They recommend the 115 grain +P in their original JHP line. The 125 +P could over penetrate due to the 3.1" barrel on the Shield. The DPX line is for deep penetration up to 18" deep and they caution using it in a crowded setting such as a mall which seems to contraindicate the use of the ammo as a SD round to me but that is what their tech people told me. I will report back once I put 100 rounds down range this weekend. For the military amongst us, Corbon offers a nice discount!

While all of the Speer "short barrel" loadings are tough to find right now, the 9mm 124grn +P in non-short-barrel is quite plentiful. In the case of the 9mm, both of the 124grn +P loadings perform very similarly. I wouldn't be worried to sub in the standard Speer 124grn +P in a 9mm sub compact such as the Shield.