Yeah pretty sure its 223 wylde. I want 16'' or 16.5'' 5.56 goodness to go under this new MI free floating rail I just got...
If its .223 Wylde (not Remington) then its the new improved chamber that will run .223 Remington & 5.56 Ammo while providing better support and performance for both rounds.
It's a better chamber than a 5.56 chamber