5.7x28mm: History or Zippy Future? The 9x19mm NATO cartridge just seems like a fact of life today. I don’t mean to say that ungratefully, really, but it’s an undeniable force inside the firearms world. Yet, this favored child was once put on the chopping block of history by no less than NATO itself – well, to the extent a bureaucratic design request really spells doom for the status quo. But that begs the real question, “Why?” Certainly, the 9mm round has proven itself effective enough for most modern militaries and law enforcement agencies. It’s practical, common, controllable, and functions well in the modern lineup of semi-auto pistols. So, what did the 9mm do to give NATO cold feet?