5.56 is a hotter load. More pressure, which is why it is not recommended to fire 5.56 ammo in a .223 Cal. Rifle.
.223 ammo is fine to fire in 5.56 Rifle.
I’m trying to stick with 5.56 American ammo. Thanks for the good advice.
BLOAT! (Buy lots of ammo today) The sales figures drive the left crazy.