I've never had an issue mixing and matching COMMERCIAL ammo between 5.56 and .223 chambers. As TAK pointed out this does not always apply to military ammo. In addition my full boat 5.56 loads are to warm for a .223 chamber in an AR, but work fine in the .223 bolt rifles I've tried them in.

Of course, just because I do it, doesn't mean you will want to, but those are my personal experiences.


You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.

You cannot over estimate the unimportance of nearly everything. John Maxwell