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First off, working pressure, and speeds, do not go hand in hand.
Sammi has 9mm at 35K max, while 9mm Nato can have a working pressure of 36k isntead.
http://www.lasc.us/SAAMIMaxPressure.htm
Now just because you are loading to 36K pressure, if you are using too fast of a burning power, then you could have rounds going even slower than rounds loaded to 35K with a more effective powder isntead. So when looking at data, look at the speeds you want to achieve, and which powder would be best to achieve such speeds. Also, ball/sperical power meters a hell of lot more unform per throw out of a dispenser than flake or extruded power instead. The downfall with sperical powder, it takes a slightly hotter primer to get it ignitied correctly, but in pistol, really not a problem with any of the standard primers.
Next on the list, plated bullets use less power than jacketed bullets to hit the same amount of speed/acheive the same amount of working pressure. So when loading for plated bullets, make sure that you are looking at the correct data, and not data for jacketed bullets isntead.
Note, cast bullets use even less power, and PC coating on a bullet give about 35fps more speed itself.
As for loading 124gr ammo to M882 speeds (1230fps), not going to pull it off even with cast PC bullets while staying within Sammi working pressures. So unless the pistol is rated for +P/Nato ammo, don't load to Nato/+P ammo pressures for the pistols.
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You have hit the nail on the head by pointing out that loading for pressure is a bad idea. Of course I plan to carefully load for the velocity I want while watching for indications of excessive pressure, basing my loads on published data that includes measured chamber pressures.
Lots of folks think “NATO is really hot stuff” and thus immediately think of it as at the hot end of the. +P range. This is false. A good bit of it has to do with the variety of methods used to measure chamber pressure, and some pretty odd wording in both SAAMI and NATO specs.
My experience with military M882 9mm NATO rounds and the M9 pistol was quite pleasant. The Beretta was very comfortable to shoot with GI ammo, without any indications of excessive pressure. Of course we had to “police the range” after firing, and being a handloader I checked out those primers. Not a single one was flattened more than you’d expect from a full power 9mm load.
Using published data, I can definitely find numerous loads that give the velocity I want without pushing into the +P range. SAAMI specs for standard 9mm allows a max of 35,000 PSI and for 9mm+P allows for 38,500 PSI max (both measured by piezoelectric transducer). NATO’s specs (STANAG 4090) specify a max by piezo transducer of 230 MPa, which converts to 33,358.7 PSI. The MIL-STD for GI M882 calls for a max of 215 MPa, which converts to 31,183.1 PSI measured at the case mouth.
I have found many loads that are listed as +P, and many that are not, all the while giving essentially the same velocity with the same bullet weight.
Considering that Winchester’s 9mm NATO load actually qualifies when fired in a 7.84” barrel, and is pretty close out of a 4” barrel, I don’t worry about wrecking my guns.