EZ Buy Federal 5.56 XM855 62 Green Tip 62 Grain FMJ BT
This is the famous and hard to find mil-spec M855 Steel core Green Tip. It is loaded to NATO specs and is not intended for use in commercial or bolt-action rifles chambered in 223 Remington ammo, but is perfect for your AR15 in 5.56 cal. Each round is brass-cased, boxer-primed, non-corrosive, and reloadable. It is both economical and precision manufactured in the USA.