[MileHi]

.223 in a 5.56 chamber is fine. Otherway around could cause problems because of chamber pressure and slight dimensional differences.

[Psalm 73]

".223 in a 5.56 chamber is fine. Otherway around could cause problems...."

So, bottom line is get a rifle chambered for 5.56 NATO and you cannot go wrong - even if the worst happens and ammo is tough to come by, it would still be about the easiest rifle to find ammo for (.223 or 5.56).

Can the same be said for .308/7.62 NATO?