My only observation is; why are you using 4064 powder? It's too slow for .223, I think you're seeing signs of way TOO low pressures. Especially when you consider the very slow velocities. Might just be lack of pressure NOT creating a good seal around the outside of the primer cup.
The more people I meet, the more I love my dog
They're going to get their butts kicked over there this election. How come people can't spell and use words correctly?