Thread: See separation?

This comes across as a Sizing / Chamber ? issue but could be the choice of powder as the blacking of the neck shows pressure trying to work back around the neck before it has had a decent chance to seal the bore ? . Pressure issues can be the same for low as well as high and if the neck grips the chamber before the body it just may? pull itself apart ? .
To me the annealing is a side issue , powder and measurements , case usually ,are by far the greater possibility for problems .