Why is the 9mm NATO round loaded hotter than standard pressure? Doesn't it offer more than enough penetration in standard pressure form?

Fur use in sub-machine guns.
Standardized to ease supply chain issues.

I’ve actually heard it the other way around and that it’s factory civilian ammo is loaded light.

I believe I read a long time ago that it was loaded that way to ensure reliable function in 9mm submachine guns (presumably blowback guns). NATO standards are of course intended to ensure that the ammo can be used across all platforms used all members, so one 9mm round was intended for all NATO pistols and submachine guns.

Wouldn't be suprised,  since it's a German invention.  You'd think NATO would be the default- though I suppose it could be hotter than the initial Luger loading.

https://thehebrewhammer.net/2019/06/02/a-quick-note-about-9mm-nato-specs/

A QUICK NOTE ABOUT 9MM NATO SPECS
JUNE 2, 2019 DAVID ZAKAR

After engaging in YET ANOTHER argument online about 9mm NATO specs, I’d like to just say my piece once right here and then reference it. I have STANAG 4090 right in front of me; it’s not that hard to read, it’s just that most people have not.

American shooters have had access to M882 for years. This is excellent ammo, and I run a lot of it through compensated pistols. Unfortunately, this has also led to many shooters deciding that M882 is the NATO spec, and nothing else works. This is absolutely not the case, and I would be glad to tell you why after the break.

STANAG 4090 has some basic requirements for NATO-compliant 9mm ammo that we care about:

It’s got to be 9mm, and gives the dimensions as such.

Precision must be at least 3? at 50yds.

Bullet weight must be between 108gr and 128gr.

Energy must be between 400ft/lbs and 600 ft/lbs.

Mean pressure cannot exceed 37k PSI and 230MPa. Individual rounds can be as hot as 42.7k PSI and 265MPa.

There are some primer specs. I don’t know if I’d call them hard primers, but they’re definitely not soft.

It needs to be water-proof.

It needs the NATO cross marking on the headstamp.

If someone hands you some 9mm ammo that doesn’t meet one of these requirements, it is not NATO spec ammo. Conversely, if someone hands you some 9mm ammo that’s different than M882, that does not mean it is not NATO spec ammo.

Here are some quick takeaways:

115gr 9mm ammo is not automatically “out of NATO spec”. In fact, the new Winchester XM1152 (FMJ) ammo is in the energy spec because they run it at 1300fps.
Claims that NATO spec ammo must be +P are not quite true, but are probable given the energy requirements. Chances are good that it’s not +P+, but strictly speaking, individual rounds might be due to loading variances.

Velocity and energy are measured from a standard proof barrel of 7.85? length. This is substantially longer than your pistol’s barrel, and thus it is likely that your pistol’s barrel will not produce results as spectacular as the NATO spec demands. HOWEVER, pressures will still be higher than most commercially loaded bulk ammo.

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This makes sense. Also, longer range for subs with hot ammo.

I have to load 9mm a bit hot if I'm running though the FA  MP-5.  It'll run the light stuff, but not as well as the hotter stuff.

I will add that hotter, full power ammo tends to be more reliable under adverse conditions, dirty guns, that are more common in war/combat.

Also, with typical soldiers covered in all sorts of gear (not even body armor) of ammo vests, pouches, straps, etc so a hotter bullet is more likely to get through it all.

I am very curious about the use of pistols and sub-guns by militaries in modern times. It must be a very small fraction. I'd personally rather have an extra rifle mag or grenade but a Glock 19 or 26 stuffed in a spare ammo pouch would be comforting.  But carrying a 2.5lb 1911 with 7 rounds would NOT be ideal.

The method used to measure pressure for commercial SAAMI 9mm ammunition is different than the method used to measure pressure for 9mm mil-spec/NATO ammunition and there is no formula that can convert pressure from one system to the other.  The velocity for 9mm SAAMI ammunition is measured from a 4” barrel.  The velocity for 9mm mil-spec/NATO ammunition is measured from a 7.85” EPVAT barrel.  The US military’s 9mm M882 ammunition has had its pressure/velocity down-loaded multiple times since its inception.

...

Did not know that. What’s a EPVAT barrel look like? How is it measured?

Electronic Pressure, Velocity and Action Time.  

It's more about the different transducers used and the different locations on the barrel that the pressure is measured than the exact make-up of the barrel per se.







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IIRC, I saw a Winchester box with NATO labled on it claim a bullet weight/velocity that struck me as standard pressure.

I didn't know they used a 7.85" barrel for velocity testing. Is that now as well? My memory is telling me the M1152 ammo shows velocity near what is claimed on the box using the Sig 320.

Do you like the latest M1152 flat nose ammo?

@molon

Interesting how the STANAG documents that were posted show the bullet weight on the FMJ rounds to be 112-119, not 124-124.

The stuff for the M3 SMG seems to be equivalent off the shelf 115gr FMJ range ammo....

This. When ole Georg invented the 9mm for the Luger he loaded them hotter than we have to today so that the Luger would function. If you have a Luger and it will not function (they are very finicky) try some 9mm NATO and it probably will run. I know my Luger likes the stuff.

I know the Sig 124gr ammo my buddy shoots (Army SF) is loaded super hot.

He trains a ton and routinely blows up RSAs in his G17s and G19s at around 4-5,000 rounds

Shoots a ridiculous amount of 855A1 as well.

What is an RSA? Glocks can handle some really hot ammo. I know they shoot some really hot 9mm in India and were using Glock 17's

Recoil spring assembly.