+p ammo in full size mp 40???

[luis032557]

Has anyone shot +p ammo in full size mp 40? The manual says not, that it could mess up the barrel. Has anyone shot this type of ammmo through this pistol??

[Fishinfool]

I don't believe there is a "+P" rating that is recognized for the .40 S&W by the SAAMI.

Larry

[luis032557]

Well do you know if it will mess up the barrel or the gun for that matter

[hardluk1]

The P+ is udes as an advertising gimmick but some of the "p+" ammo can blow the brass out as many barrels don't offer full chamber support. I do not have a 40 m&p pistol but do use underwoods 155gr 1300fps ammo in my tp40 kahr . I would not run it in a glock 27 gen 3 I had .
Heres a photo that shows a few chambers to judge yours by.

http://img.photobucket.com/albums/v2...asesupport.jpg

Note that some handguns are made to handle the higher pressure of the 357sig cartridge and general strength would not be an issue but the back of the chamber can be.

[shot1971]

I had a Glock 27 & it handle +p+ ammo very well. In fact I have fired +p+ ammo in my Shield 9 even though the owner's manual does not approve. But I keep +p ammo in my Shield.

[mustangman]

Originally Posted by luis032557

Well do you know if it will mess up the barrel or the gun for that matter

I don't know that anyone can answer this question for certain about your gun, but S&W obviously thinks that it might, so I wouldn't take a chance. If you do end up with a problem gun from using it, youre on your own, no S&W warranty. I know Buffalo Bore, and Underwood advertise 40 +P, but I think that the regular 40 stuff that is available from all the major manufacturers is plenty "hot". Just my opinion though, to each his own.

[Prasko]

There is no saami spec for +P .40.

S&W only warranties up to saami specs.

If you feel like you don't want your warranty, or possibly want your gun to explode, by all means, test your luck.

[Venenoindy]

There is not +P .40 S&W, if a manufacturer labels as such I wouldn't buy it or use it. The .40S&W is a high pressure round to begin with and if some irresponsible people are purposely over charging the round is just a disaster waiting to happen.

[Mountain Walker]

So little or nothing is gained by hot loading ammo. Rather in selecting ammo or reloading components I look for a good quality bullet and standard pressure. Those loads that exceed standard pressure also lead to premature wear, malfunctions, and sometime firearm failure. If you want more power get a bigger caliber or a long arm.

[Wolf1775]

It's been pretty well covered already, but...

There is no +P for .40 S&W. You can load the round to max recommended loads and pushing hotter until you see signs of pressure, but that's pretty damned unsafe.

Best case scenario with pushing the limits of safety is that you wear parts out faster. Worst case scenario is that you blow the gun apart. Simply put, don't do it.

The only reason I would load rounds on the hotter side is to make majors in pistol matches. Otherwise, I'd rather find good components that perform well together and are well within safe limits to get the most out of my gun.

[hardluk1]

So much factory loaded ammo by the big boy companies has been reduced from it designs standards for there higher production runs so there less chance of screw that they have to deal with. It happens enough as it is. Buy a bow of ammo and pick 10 random rounds out and chronograph them and do it again with a underwood , BB or Georgia arms and a few others and see the spread in fps between round drop in a major way. These boutique companies run ammo at a low level of production and use a stable quality brass like Starline and just make a better product than what you get from remmy, winny fed and the likes.

Its not for ever one or ever handgun. Also many of the problems with 40sw is found with 180gr loads and pressure issues that don't show with 155 or 165 gr bullets.

Heres a bit of reading for the 40sw loader.

Speers 155gr factory load is 1200fps , mine from underwood 155gr same speer bullet is 1300fps, using a better controls during loading and better brass. I can shoot these loads and turn around and the brass drops clean back into and out of the barrels chamber with no flatting of the primer shown do to high pressure. Try that with the slower lower pressure 40sw ammo you use now and see how that works out.

These pistols were designed to handle the higher pressure 357sig cartridge and use the same recoil spring as a 9mm?? That could be part of the early unlocking issues m&p's are known for. Could also be part of any problem you have with group size. I going to look at heavier springs from wolff to try with our 9mm and some underwoods hotter laods for velocity and group size.

You can also note that corbon uses starline brass and there 165gr hp load runs at 1150fps from a 4" glock where underwood advertises 1200fps and meets that velocity in a 4" barrel just like corbon load does. That's only 50fps faster . Some companies spread in velocity is more than that 50fps.

[Ofc.JL]

What ever body else said. .40 S&W is already at +p pressure. It's how the round was developed. That's why S&W's first .40 cal pistol(the 4006) didn't hold together well. S&W used the 59(9mm) series of guns basically bored out to.40, and over prolonged shooting, the 4006 was just not holding up. The pistol was getting literally beat to death from the pounding. The .40 S&W round being "hot", so to speak is the reason Glock went to the 3rd pin in it's pistol frame. They were having the same problem with the .40 round beating the cam block out of the plastic frame. I believe that is also the reason the M&P series of pistols have their stainless steel subframe. Stops the flex and stretch in the polymer frame when shooting the .40. .40 S&W is a hot round to begin with.
Anyone advertising "+p" .40 is loading past SAAMI specs. S&W says don't, then don't. You are flirting with disaster.

[soad]

There is p+ in the .40

It's called a 10mm....go get one.

[Johnmuratore]

I've got a 40c and the manual that came with it.
I've read it from end to end and there's nothing in there about a +P round messing up the barrel.
Where does it say that?

[Wolf1775]

Originally Posted by Johnmuratore

I've got a 40c and the manual that came with it.
I've read it from end to end and there's nothing in there about a +P round messing up the barrel.
Where does it say that?

+P rounds won't be mentioned because there is no standard for what constitutes a +P round. There are minimum and maximum suggested loads, but that's it. When people discuss +P rounds with .40 S&W they tend to mean that they're loading rounds either on the upper edge of what's considered a safe maximum load or they're loading past that to squeeze out more velocity.

The former can be done safely depending on the condition of your brass, the primers used, bullet weight and material, barrel rifling, consistency from round to round, and experience. The latter moves into dangerous territory since you're now going beyond what's been found to be safe tolerances for the round.

Even when one of my friends is loading to see how far he can push that powder/bullet combo, he starts at .3 grains under the max and steps things up by .1 grains to see where pressure signs start. Then he dials it back by .2 grains just to be on the safe side since that'll allow some breathing room.

[1hatchet]

Originally Posted by Johnmuratore

I've got a 40c and the manual that came with it.
I've read it from end to end and there's nothing in there about a +P round messing up the barrel.
Where does it say that?

What the manual does say is the below:

"You are responsible for selecting ammunition that meets industry standards and is appropriate in type and caliber
for this firearm.
Never use a cartridge not specifically designated for use in your
firearm. The wrong type of ammunition may exceed the capability of your firearm and may damage or even rupture your firearm."

SAAMI | Sporting Arms and Ammunition Manufacturers' Institute

[2hawk]

Here's a fired .40 +P case


Luckily, it was fired in a steel frame gun.
"Ya pays yo mony, ya takes yo chances."
Or not. Plenty of good quality .40 ammo to had.



ETA- This wasn't factory ammo, it was a reload that was trying to be a "+P"

[WR Moore]

Originally Posted by hardluk1

These boutique companies run ammo at a low level of production and use a stable quality brass like Starline and just make a better product than what you get from remmy, winny fed and the likes.

While not all boutique ammo companies push the envelope, some do. Before you tout the qualities of their ammo, check with SAAMI and see if they're members. I know of several boutique ammo companies who are no longer in business due to lawsuits.

And yes, there is no .40+P standard. There is a least one company that uses the rating for advertising purposes.

These pistols were designed to handle the higher pressure 357sig cartridge and use the same recoil spring as a 9mm??

Actually, the 357 Sig operates at the same pressures as .40 S&W. The recoil spring may be the same for several calibers, slide weights aren't.

[hardluk1]

Well what do you know one other guy has figured it out. Advertising trickery buy some. Just have a supported barrel and recoil springs for the job.

Acually the 357 sig saami is designed to 40,000psi ,not the same as the same 35,000 of the 40sw. But you could be right that the larger ammo companies don't load to a 40,000 saami scale but to a lower "safer" level. 40sw may be the same and loaded lower too by the same companies.



2hawk Show the base of that brass. Looks like something other than starline maybe a glock pop, no fully supported chamber or not fully in battery when fired. RP maybe??
https://www.starlinebrass.com/brass-...0-Super-Brass/

[2hawk]

hardluk1 - you know what you're looking at That blown brass is RP.

That was a reload at the top of the loading chart, maybe even a bit over. And yes, I think there's a good chance that case had been "glocked".

I just wanted to show what can happen when you go seeking something that is over spec. In this case it wasn't catastrophic, just blew the floorplate off the magazine and unloaded everything, including spring and follower, at the shooter's feet. But, in a plastic gun, the results may well have been quite a bit worse for gun and shooter.

Almost every type of ammo made has a bigger faster version, ie, .40<10mm, .45acp<.45 Super or .460 Rowland, .38<.357, etc. IMHO, if you want more than what SAAMI spec is on a round, then you really want a different round.

[shawn mccarver]

Originally Posted by luis032557

Has anyone shot +p ammo in full size mp 40? The manual says not, that it could mess up the barrel. Has anyone shot this type of ammmo through this pistol??

Plus-P in a .40? What will they think of next.

Why don't you just FOLLOW THE INSTRUCTIONS of the manufacturer?

[Johnmuratore]

Yep, what Shawn said.

[John R]

Sure are getting a lot of threads on 40+P, there is no such thing.
Wonder where these guy's are finding this stuff?

[MichiganScott]

Originally Posted by John R

Sure are getting a lot of threads on 40+P, there is no such thing.
Wonder where these guy's are finding this stuff?

I'd never heard of it either. Turns out Buffalo Bore sells it and you get quite the disclaimer about "fully supported chambers", etc. The velocities they claim are right up there with 10mm.

[hardluk1]

Had to edit this. After reviewing the many different 40sw factory loads are avalible for ammo companies and the large spread in velocity thru them how about you all writing down the one's you would run and those your afraid of as some of the companies come with in the difference of the extreme spread in velocity typical found in a cartridge when test on a chronograph. The difference in real world between a corbon and underwoods ammo can be very small when run thru a chronograph. So I'm guess most of the guys would not use corbon ether

Michigan scott You may want to brush up on 10mm history as it was designed to throw a 170gr bullet at 1300fps and 200 at 1200fps. Makes me wonder what under powered junk you have used.

[scooter123]

There seems to be some misunderstandings in this thread, so lets clear things up a bit.

1) There IS NO 40 S&W +P ammunition out there. Those who choose to label their hotter variant loads of this caliber are doing so without the consent of SAAMI and because of this that labeling is technically a Trademark violation.

2) Muzzle velocity is a result of more than just pressure, it's also determined by barrel length and the burn rate of the powder used. Use a fast powder and a maximum pressure load will only produce velocities that most would consider low, target grade ammo. However, loads featuring a fast powder will show less variation in the produced velocities when you compare a short barrel to something in the 4 inch length. Use a "slower" powder and your produced velocities will go up even if the produced pressure is only at low to midrange levels. However, that slow powder load will lose a lot of velocity in barrels under 4 inches and the muzzle flash and blast can become objectionable.

Then there is the matter of Barrel Length, or what I refer to as the The Great Ballistic Lie. People tend to purchase self defense ammunition by looking at the Numbers for Muzzle Velocity and Energy. IMO it's a rather foolish way to choose ammunition but the simple fact is that there are a lot of fools out there. Because of this many manufacturers will list ballistic results that most of us will never see because we don't test our ammunition using a fire lapped 10 inch barrel, they are not only inconvenient to carry but the fire lapping process really reduces the service life of the barrel. However, that doesn't stop the ammunition and reloading powder manufacturers from using these technique to hype their performance numbers because those numbers do sell.

Now to address the original subject. Since there isn't any +P designation for the 40 S&W the question is moot. Or, it should be posed as "should I try over pressure ammunition in my M&P". When you ask it that way the answer become rather obvious. Because most people with any sense at all will avoid using overpressure ammunition in any firearm they are actually holding in their hand(s). Bad things can happen when a firearm blows up and sometimes the results can be Fatal.

PS; the one ammunition manufacturer who I have found to be 100% honest in their ballistic claims is Speer, specifically in the Gold Dot and Lawman line. If they claim a muzzle velocity of 1150 fps from a 4 inch barrel you will find that your muzzle velocity out of your 4 inch handgun will meet that standard or, in the case of Glock, may exceed that value. I've chronographed the 40 S&W Speer Gold Dots from my Sig P229 and they clock right at 1150 fps. I've also clocked their 230 grain 45 ACP Gold Dots from a Ruger SR1911 and they came in at an average of 910 fps, only 5 fps higher than what was listed on the box.

[NJM15]

Originally Posted by luis032557

Has anyone shot +p ammo in full size mp 40? The manual says not, that it could mess up the barrel. Has anyone shot this type of ammmo through this pistol??

A guy at the range was shooting it out of his glock and cracked the barrel, its equivalent to overmaxing a reload

[NJM15]

Originally Posted by John R

Sure are getting a lot of threads on 40+P, there is no such thing.
Wonder where these guy's are finding this stuff?

Heres some, I shot one round and gave the rest away

[1hatchet]

Interesting Underwood Ammo no longer lists any .40+P on there web site but do list some .40 at Muzzle Vel. of 1442 fps.

40 S&W 135 Grain Jacketed Hollow Point Box of 20

[scooter123]

Looking at my Lee 2nd a compressed 11.5 grain charge of Longshot with a 135 grain jacketed bullet will yield a velocity of 1434 fps at a pressure of 31,900 psi, which is 3,100 pis below the SAAMI maximum for the 40 S&W. So, by careful choice of a suitable powder that Underwood load is feasible and not that close to the maximum pressure for this caliber.

As for shooting that particular load, as someone with a fair bit of experience using Longshot in the 40 caliber I would expect that load to sound a LOT like a full house 357 Magnum. It will also batter the firearm a bit (a stronger recoil spring is advisable for continued use of this load) and will likely lead to issues with flinching. To put it simply, you'll see lots of muzzle flash, it will be quite loud, and it may hurt a bit if you try it in a light weight semi auto.

[hardluk1]

When underwood first started loading ammo they followed buffalo bore way with the +P on the 40sw as an advertising trick. If you ordered a box now IT now it will not say +P on the box but have the same velocity as it test below the saami 35,000psi design standard for a 40sw.

I not say'n you want to run this ammo in a badly designed chamber or with standard pressure recoil springs . MY 40sw is not a m&p , ours are 9mm and run just fine with the underwood 124gr real +P ammo so just common sense in the ammo you use. IN ANY FIREARM.



scooter123. Watch some of the you tube videos . The underwood ammo smokes no more than speer or georgia arms or other premium brands and for me the recoil is no worse than speer gd loads or Georgia arms defense ammo. Maybe that is because of the heavy recoil system kahr uses or what an ole fart shooter feels. Easy to control a mag dump in a 23oz single stack kahr. Very different recoil from a 4" dw revolver in 357for sound or snap. Rather shoot the 40 any day than may 357 loads. guys forget is very easy to push a 170gr speer sp at 1400fps + in 357. That rounds come live with heavy bullets. But just one ole guy's opinion .

[Johnmuratore]

Buffalo Bore sells +P ammo in .40 S&W.
Listed at 1140fps with a 180gr bullet.

Only +P I've seen.

[robkarrob]

From the Buffalo Bore Website: https://www.buffalobore.com/index.ph...t_detail&p=115

Heavy 40 S&W +P Pistol Ammunition

Heavy .40 Smith & Wesson +P Ammo - 155 gr. (1,300 fps/M.E. 582 ft. lbs.) - 20 Round Box


That Buffalo Bore is pretty strong ammunition, especially the 582 ft pounds of energy.

I use CorBon 40 S&W with a 135 gr bullet and it specs at 1325 fps and 526 ft pounds energy. It is very close to maximum SAMMI specs for pressure, so I would think the Buffalo Bore exceeds SAMMI pressure specs. I would not trust shooting this particular Buffalo Bore ammunition. It specs at over 10% more energy than the highly powerful CorBon.

This Buffalo Bore might cause a "KABOOM" in my Shield 40. They have many warnings about not using this ammunition in "unsupported" barrels, and my Shield barrel nearly fully supports the cartridge and I would not use it.

Bob

[dullh]

"+p ammo in full size mp 40???"

There's no such thing as +P ammo in .40 S&W.

SAAMI (Sporting Arms and Ammunition Manufacturers Institute) is the "body" that sets pressure standards in the US. They have not set an over-pressure (+P, +P+, etc.) standard for anything in .40.

If Buffalo Bore or anyone else is using +P on their boxes or in their advertising they are doing so on their own.