Hi Robert and welcome. Since the barrel is stamped .223REM, for safety and warranty purposes, you should only fire .223 ammunition and not the higher pressure 5.56NATO ammunition. Cheers, stay safe and enjoy!

Robert, unfortunately no these are specifically rated for 223 so you cannot fire 5.56 safely out of this. Firearms Chambered in 5.56 can safely fire both but 5.56 has a higher chamber pressure so cannot be fired threw a 223 rem. Sorry but hope this helps.

Hi Robert, no sir, this is rated for .223 only.
Stay safe & have a great day!