[Berlin_Freeper]

The 5.56×45mm NATO (official NATO nomenclature 5.56 NATO, but often pronounced "five-five-six") is a rimless bottlenecked intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal.

[M Kehoe]

Good job.

I have an alias. 7.65 x 39.

5.56mm