223

The .223 Remington is a rifle cartridge, developed in 1957, for the ArmaLite AR-15. In 1964, the ArmaLite AR-15 was adopted by the United States Army as the M16 rifle, and it would later become the standard U.S. military rifle. The military version of the cartridge uses a 55-gr full metal jacket bullet and was designated M193. In 1980, the .223 Remington was transformed into a new cartridge, a 62-gr full metal jacket bullet with a 7-gr steel core for better penetration and designated 5.56×45mm NATO (SS109 or M855).

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