With some gun manufacturers warning against the use of +P, and +P+ ammo in their weapons, what 124gr 9mm velocity out of a 4 - 5? barrel would be considered +P if not designated as such? The reason I?m asking is that Kel-Tec is pretty clear in regards to their Sub 2000, don?t do it. One example would be Winchester 124gr USA Valor, it?s marked as NATO, but nothing about a +P rating, which are likely one in the same, and has a suggested velocity of 1,200 fps. Many of the common brands as seen below are easier to pick out as being fine, but what about Sellier Bellot 9mm 124 gr, clocking in at 1,181 fps, which seems to be right on the edge of standard pressure and +P, which I have a bunch of. I?m thinking 1,180 would be right on the edge of std pressure and +P, Thoughts?

Ken

         Standard Velocity

Federal Syntech 9mm 124 gr - 1050

CCI Blazer 9mm 124 gr  - 1090

Magtech 9mm 124 gr - 1109 fps

PMC 9mm 124 gr - 1110
_______________________________
           
     Questionable Velocity

Winchester USA Valor NATO 9mm 124gr -  1200 fps

Sellier Bellot 9mm 124 gr - 1181 fps
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               +P Velocity

Federal HST 9mm 124 gr +P - 1200 fps

Speer Gold Dot 9mm 124 gr +P - 1,220

9mm Plus Pressure Plus  Charles E. Petty
Basicly..... Is it worth it to beat the snot out of your firearm for a little extra?

The current SAAMI (Sporting Arms and Ammunition Manufacturing Institute) standard for 9mm Luger ammunition specifies a maximum product average chamber pressure of 37,400 p.s.i., but, the +P+ loads exceed this by a substantial margin. A limit of 42,000 p.s.i. has been proposed for this ammunition. For comparison, proof load pressure (nominal average) is set at 49,800 p.s.i. Now the situation is even further confused, for Remington has begun to market +P 9mm Luger ammunition with a proposed pressure limit of 38,500 p.s.i. To clarify, +P ammunition is available for commercial sale while +P+ loads are not.
All of this raises the question of what the civilian shooter can use in his gun. Even though the ammunition manufacturers take pains to insure that special law enforcement loads do not circulate in civilian channels, it is unrealistic to expect that some will not "leak" out. The same is certainly true for M882 service ammunition, and it is important that the civilian shooter who encounters any of these loads be able to recognize them and understand that this ammunition is different. M882 NATO ammunition as loaded by Olin Corp. (Winchester) and formerly loaded by Federal is currently specified to drive a 124 grain FMJ bullet at 375 meters per second (1230 f.p.s.), which puts it in nearly the same league as the various +P+ loads.

Thanks Wade, so in my thinking, right or wrong, it would seem like the Sellier Bellot 9mm 124 gr running at around 1,181fps would be right on the edge of standard and +P pressures, or am I looking at this incorrectly? I probably wouldn?t have given this much thought, but after speaking with an engineer at Kel-Tec regarding +P loads, all he said was ?Just Don?t? I?m pretty sure limited use of +P would be just fine, as with other firearm manufacturers, just not everyday all day

Published SAAMI spec data for 9mm Luger shows a max pressure load at 35,000 PSI Transducer MAP producing 1,130 fps from a spec chamber and a spec barrel (4" from case head to muzzle.)

I would say anything over 1,160 from a 4" barrel has probably exceeded 35k PSI MAP.  It has not reached max +P yet, but probably over standard.

Anything listed "NATO", assuming is is loaded to NATO spec, is going to be way over standard pressure 9mm Luger.  The NATO spec is definitely an over-pressure spec.

Thank you both

Ken

Ken, I sure wish Alliant had pressure values for the newer powders these days as that would shed more light on the real values.
It is also why I try the maintain the older data that does have pressure values listed.

The current SAAMI (Sporting Arms and Ammunition Manufacturing Institute) standard for 9mm Luger ammunition specifies a maximum product average chamber pressure of 37,400 p.s.i.

Ken if you look at this Alliant data these are standard 9mm loadings with their pressure values.


Lyman Data


Hodgdon Data  Just make sure you are looking at the 9mm listings

9mm listings continued

Thanks Wade, these are very helpful

What are the key differences between a 9mm and a 9mm P+? +P denotes higher than standard pressure - for 9mm, SAAMI standard pressure is 35,000 PSI. 9mm +P is 38,500 PSI. This higher pressure results in an increase in muzzle velocity, which results in various ballistic differences such as a flatter trajectory.

Thanks