In general, military ammunition is pretty generic, they have to be, to be used in so many different military firearms and allies. As soon as you go to the civilian cartridge version, things change as the cartridge is then loaded for a specific requirement, which doesn't necessarily equate to the military specification. Similar to handloading for your rifle.

Of course batches military ammunition aren't all identical, certain batches can be markedly hotter than others while being still within the military acceptance specifications. Or more accurate, or with softer brass, etc.