Four rifles, four different cartridges, four different dies and all once or twice fired.To me, it looks like the normal expansion of the case. When the cartridge is fired the pressure expands the body of the case to fit the chamber but the brass is too thick at the very bottom of the case to expand it that much. Then when you size the case, the die only contacts that portion of the case that has expanded out to the chamber walls.
If you look very carefully at a fired case before you resize it, you can see that ring on a fired case too. It just hasn’t been burnished bright by contact with walls of the dies and the little tarnish on the cases makes it more apparent.
Unless those primed cases have been in pretty adverse conditions, there’s no need to deprime and size again.
Last edited by navlav8r; 03/14/24.
