I have seen that happen a few times ,, I too blamed the ammo ,, however to fix the problem I had to put new firing pin spring in ,,, Just my 2 cents
Anyone have light primer strike problem with American Eagle AR223 #ae223bl. Black box ammo? I’m using a cz527 and getting quite a few. Mil spec primers?
Check the firing pin to make sure it's not damaged, chipped etc. Check also the firing pin channel/recess to make sure there's no crud slowing down the firing pin strike.
AE does not have hard primers.