9MM, "the element of operation." This design mimics the periodic table of elements.
The 9×19mm Parabellum (abbreviated 9mm, 9mmP, 9×19mm or 9×19) cartridge was designed by Georg Luger and introduced in 1902 for the Luger semi-automatic pistol.
Attempts to improve ballistics of the cartridge came in the early 1990s with the widespread availability of high pressure loadings of the 9 mm cartridge. Such overpressure cartridges are labeled "+P" or in the case of very high pressure loadings "+P+".
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