[bravotu]

WHAT?
You are Kiddin’ Right...?

Get one chambered for 5.56 vice .223, there is a difference. Although the rounds are externally the same, the 5.56mm is a hotter round which might cause a rifle chambered for .223 to fail. This is something to consider if civilan sources dry up and all that’s left are military spec rounds.

That’s Absurd!
Ain’t NEVER Heard That Before.....

[mylife]

My 5.56 High Standard eats both.

It does not care.

[PLMerite]

All I know is what I read:

http://www.ar15armory.com/forums/556-223-Ammunition-Ch-t22582.html

[smokingfrog]

Here's the problem. Many NATO cartridges have bullets that will become jammed into the rifling of a SAAMI chambering (the throat is too short). This is VERY DANGEROUS, for a grat number of reasons.