Botach Tactical sells IMI SS109/M855 ammo (green-tipped), IIRC and [url]www.ammoman.com[/url] has some BOSNIA & HERZEGOVINA made, M855 which I think is probably a good NATO spec ammo. He guarantees what he sells, it's hit and miss w/ Botach, (call to make sure they have it in stock, is your best bet w/ them).
FWIW, I stock the IMI M855/SS109 stuff as it is good hot NATO ammo.
Hope you've read the AmmoFaq: [url]www.ammo-oracle.com[/url], it's a good reference for 223 ammo.
Mike