9mm Ammunition

The 9mm, or 9x19, 9mm Luger, or 9mm Parabellum, is far and away the most widely-used service pistol round on the planet. This Wikipedia intro sums it up:

The 9×19mm Parabellum (abbreviated 9mm, 9mmP, 9×19mm or 9×19) cartridge was designed by Georg Luger and introduced in 1902 by the German weapons manufacturer Deutsche Waffen- und Munitionsfabriken (DWM) for their Luger semi-automatic pistol.^[6] For this reason, it is designated as the 9mm Luger / 9mm Luger +P by the SAAMI ^[7] and the 9 mm Luger by the C.I.P. (differentiating it from the 9mm Makarov and 9mm Browning cartridges). Under STANAG 4090, it is a standard cartridge for NATO forces as well as many non-NATO countries.^[8]

The name Parabellum is derived from the Latin: Si vis pacem, para bellum ("If you seek peace, prepare for war"), which was the motto of DWM.^[9][10]

According to the 2006 edition of Cartridges of the World, the 9×19mm Parabellum is "the world's most popular and widely used military handgun cartridge."^[11] In addition to being used by over 60% of police in the U.S., Newsweek credits 9×19 pistol sales with making semi-automatic pistols more popular than revolvers.^[12] The popularity of this cartridge can be attributed to the widely held conviction that it is effective in police and self-defense use.^[13] Its low cost and wide availability are self-sustaining contributors to the caliber's continuing popularity.

The popularity of the 9mm continues to this day, and shows no signs of letting up.