Just to add a bit more confusion, the 9mm case, since it is tapered, may or may not headspace on the case mouth. The case is a cone, going into a cone-shaped hole. When the two cones meet, the case stops, whether the case mouth has reached the front of the chamber or not.
And Kyrie, where did those pages come form Did the Army really print technical data on 9mm cartridges that lists the bullet weights as 182 and 179 grains?
Finally, the MAP, Maximum Average Pressure, is a ceiling, not a goal. If an ammo maker can get the velocity they want, at a lower pressure, they will. So, if the goal is (for example) a 115 grain bullet, at 1,200 fps, and they can do it with the powder you have, at 27,000 PSI, then they'll do it.
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