9mm +P+ vs 9mm NATO pressures...

[Mike Irwin]

OK, this got caught in the middle of a developing flame fest, and was originally a question for Mark IV.

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Mark,

Ok, the fault may possibly be mine, here.

It is my understanding that ammo loaded to 9mm NATO generally IS the equivilent of American +P+ ammo, possibly a little more.

If I'm wrong about that, and +P+ is loaded to higher pressures than 9mm NATO, please let me know.

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Anyone know for certain what the pressure ranges are for these two rounds?

I know that +P+ is somewhat nebulous.

[Mark IV Series 80]

Hello Mike,

Yeah, that's too bad when your discussion gets shut down by some unrelated flame war.

We were talking about SAAMI, 9mm+P, +P+, and NATO pressures a while back on TFL:

http://www.thefiringline.com/forums/showthread.php?s=&threadid=94852&highlight=SAAMI

Close to the end of the thread, stans and JohnKSa give us some 9mm pressure values.

[WESHOOT2]

+P+ means NO SET VALUE.

[Mike Irwin]

Wes,

Yep, I know that +P+ has no set value, but it's got to have a logical limit set by the manufacturers due to envelope limitations...

[C.R.Sam]

+P+ is not a SAAMI peak pressure spec.
One manufacturers +P+ may be 111% of SAAMI spec for that cartridge and another's may be 125%.

Designation determined by the individual manufacturer.

With NO direct bearing on bullet velocity.

Sam

[harrydog]

So since +P+ has no set pressure limits, it would seem risky that H&K advertises their guns as built to handle the abuse of +P+ rounds. I guess that's a tribute to H&K's quality engineering.

[JackNKoch]

standard-pressure 9mm=37,400psia
9mm+p= 38,500psia
9mm+P+=40,000 ???
9mm NATO=42,000-43,000psia (pounds per square inch, absolute)
9mm"proof loads"=49,800

I got these numbers from the M/S books. Only the first two are SAAMI defined. The Europeans do things differently than SAAMI.


The boxes of Winchester NATO I have (Q4318) read that they are loaded 10% higher than industry standard. I have seen advertisements for this ammo claiming over 1200fps and more than 400fpe for a 124 -gr load. This load supposedly uses a thicker walled case than standard 9mm Luger, also.

According to the labels on the boxes, the Winchester +P+ Ranger ammo I have is loaded 20-25% higher than normal or 40,000 CUP (COPPER UNITS of PRESSURE). This includes the RA9SXTP (127-gr @ 1220fps+) and RA9115HP+ (115-gr @ 1300fps+).

I would take that to mean the Winchester +P+ loads are between 44,880-46,750psi while the NATO loads are about 41,140psi. Reportedly there exists some hotter military 9mm that is designed only for certain submachineguns and is NOT to be used in any handgun. Still looking for all the answers to this question myself.

[JackNKoch]

Standard 9X19mm may in fact be only 35,000 psi.

This could then mean that +P+ loads are possibly 42,000-43,750 psi while some NATO loadings are closer to the +P designation of 38,500 psi.

Based on the Navy/Crane and Secret Service 9mm ammo tests (as reported in "Street Stoppers"), there seems to be some overlap between the NATO and +P+ rounds. Temperature and powder positioning can make a VERY big difference.

Also of interest is the pressures generated by the heavy nines even in standard pressure loadings as defined by SAAMI. The 147 grain nines generally produce higher pressures than the 95-124 grain standard pressure offerings. In fact under certain circumstance a "standard pressure" cartridge (especially the 147 grainers) may actually give a higher pressure reading than a 115-124 gr. NATO or +P+ loading (even under identical conditions).

[JMC]

While I can't post any scientific data on pressures for the various 9mm rounds I have fired, I can tell you that I shot the Winchester 124gr. NATO (Q4318) yesterday thru my Walther P99 and Glock 17 and was not impressed with the velocities that I measured.

I have read where they get 1250 fps with this round. I couldn't get that. I was expecting more than what I got. :(

My Winchester white boxes also indicate that the rounds are loaded 10% higher than industry standard. If so, I would expect somewhat higher velocities.

All velocities are avg. of 10 rounds
Temp was 45 degrees
Readings taken 5' from muzzle
PACT chronograph

P99 - 4" bbl.

1184.5 fps
1187.4 fps

G17 - 4.92" bbl.

1214.6 fps
1228.6 fps

I can get 1187.1 fps and 1186.4 fps thru the same P99 using a handload of 4.4gr. of Hodgdon Titegroup with a R-P or Win. 124gr. FMJ bullet in a W-W case and Fed. 100 primer and this load is not listed as a +P loading.

Also, the accuracy at 25yds. using both guns left a lot to be desired.

[JackNKoch]

BrokenArrow has posted 39,200 psi for some C.I.P. spec European ammo (like Fiocchi). Also claimed US M882 NATO loaded to 36,250 psi.

SPEER Gold Dot 115 gr. +P+ loaded 22% higher than ANSI/SAAMI standards. I figure that to be 42,700 psi and not the 40,700 psi quoted on one website.

From www.mullinsammunition.com
"All LAPUA cases are tested with 30% overpressure, according to C.I.P. regulations."
That should make standard 9mm brass good for 45,500 psi.

Also, remember that flash suppressant and high bullet pull weight can increase pressure without increasing velocity. BTW, the Winchester Q4318 specs at 1230 fps.

[taco]

I don't have any way to measure pressure but few months ago I chronographed some (15 rounds) NATO ammo given to me by a friend in the military.

From my Beretta 92FS I got following measurement along with some other commercial loads measured on the same day for comparison:

NATO 124gr FMJ - 1,180 fps avg.
Remington 115gr JHP +P - 1,260 fps avg.
Corbon 115gr JHP +P+ - 1,290 fps avg.
UMC 115gr FMJ - 1,140 fps avg.
Winchester 115gr JHP Silver Tip - 1,170 fps avg.
Geco BAT 86gr (?) - 1,430 fps avg.

I was suprised by the low velocity of the NATO ammo. I thought the ammo was loaded to pressure higher than +P so I expected to be around 1,250~1,280 fps. Also, the recoil didn't fee any different than UMC ammo and definitely less than Corbon.

[JMC]

BTW, the Winchester Q4318 specs at 1230 fps.

If so, it must be out of a barrel longer than what I used for my tests. Possibly the Beretta 92 will reach the magic 1250 fps quoted. My ammo is marked WCC 01 so it's new enough.
I get the feeling the NATO ammo, like a lot of other ammo on the market, is over rated in the velocity department.

BTW, Federal advertises a velocity of 1120 fps for their 9mmx19 124gr. +P EFMJ round (P9CSP1) with no barrel length given.
In my P99 4" barrel I get 1138.6 fps and 1140.1 fps. An average increase of .98%. Go figure.