I'm done with my experiment. I'm not gonna reload the stuff so the brass is already back in the fired brass box. I had some of that 7.62 X 39 brass that was really difficult to size down when I ran it through the 6.5 Grendel die. There is a ring around the head of the brass that didn't get sized down. I'd say the chamber it was fired in was a bit over-sized.
The trick is growing up without growing old. -- Casey Stengal