.22 caliber, or 5.6mm caliber, refers to a common firearms bore diameter of 0.22 inch (5.6 mm). Both the .22 Long Rifle and 5.56×45mm NATO/.223 Remington cartridges are very widely used.
.22 caliber, or 5.6mm caliber, refers to a common firearms bore diameter of 0.22 inch (5.6 mm). Both the .22 Long Rifle and 5.56×45mm NATO/.223 Remington cartridges are very widely used.