I did a search and didnt find anything on this topic, but I am sure that it has been talked about before.
Some sources say don't shoot 5.56 in a .223 chamber and others say that it is ok.
Since there seems to be knowledgeable people on this board, I was wondering do any of you shoot 5.56 in your .223? Will any of you definately not do this? Has anyone experienced/heard about malfunctions from doing this? I have read that some of the match quality guns are prone to have problems with this, are there any other guns that might be more prone to have problems?
If your gun is chambered for .223, I would advise not to shoot 5.56. It will shoot, but it can't be good for the gun. Better to be safe than sorry, so I would just stick to .223 in a .223 chamber.