Don't 5.56mm cases have a thicker web, and thus a smaller case volume? Why not just load them to 5.56x45 data?
the reason for loading as .223 instead of 5.56 is even more simple than the pressure thing. I only have .223 dies lol and most of my cases were origanally .223 so never bought any 5.56 dies. My rifle can handle both. The main thing I was concered about was the neck angle. I know there is difference between 5.56 and .223 on the angle and wasn't sure if my .223 die would take the 5.56 angle to the correct angle. I was under the assumption that you could make 5.56 case to .223 but not able to go the other way.
I will load some up with 5.56 specs this weekend and give it a shot
No difference other than primer pocket prep. Ive found that much Lake City brass is difficult to seat primers. Be diligent about cleaning, swaging chamfering pockets. Also recommend a Hart Primer Pocket tool. Adjust tool to assure primer pocket will allow at least .003 seat below flush. Insurance against slam fires with non military grade primers.
No difference other than primer pocket prep. Ive found that much Lake City brass is difficult to seat primers. Be diligent about cleaning, swaging chamfering pockets. Also recommend a Hart Primer Pocket tool. Adjust tool to assure primer pocket will allow at least .003 seat below flush. Insurance against slam fires with non military grade primers.