The 5.56×45mm NATO (official NATO nomenclature 5.56 NATO) is a rimless bottlenecked intermediate cartridge family developed in Belgium by FN Herstal.^[4] It consists of the SS109, SS110, and SS111 cartridges. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries.^[5] It is derived from, but is not identical to, the .223 Remington cartridge.