I have 1000 rounds of once fired Winchester 5.56 brass. I know the difference between 5.56 and .223 loaded ammo, but I'm unaware of any difference in the raw brass. I do know that military (LC) brass is thicker and can increase pressure, but I'm talking about Winchester brass.

Is there any reason why I can't load the 5.56 brass to .223 specs and use it in my #10PH with it's .223 chamber??

I plan on using SB (small base) die for the first loading, then fire form and neck size after that.