Jason - you are correct about the slight difference in pressure between the two rounds, however this particular rifle can safely shoot either .223 or 5.56 ammunition. Any rifle chambered in 5.56 can safely shoot .223. Any rifle chambered in .223 Wylde can safely shoot 5.56. A rifle chambered only in .223 (different from .223 Wylde) should not be used for 5.56 ammunition. One should be able to find the exact chambering style of each barrel/rifle inscribed somewhere on the barrel of the rifle.

The 5.56 is loaded slightly hotter as you already know. The .223 can be fired in any weapon chanbered in 5.56 but not the opposite. Also the .223 Wylde can shoot 5.56 without any problems

yes it can as it is stamped and chambered for the 5.56 NATO ammo it can also use the .223 with no issues

Jason, yes Sir it is. The Barrel is "Stamped" 5.56NATO and will handle both 5.56 and 223 ammunition without any issues. I have 3 Diamondbacks and they will handle high round counts.