Thread: See separation?

Never seen that happen after a only a couple firings.
One thing I notice is that the carbon on the case appears to continue past the cartridge neck and onto the shoulder. To me this would indicate that the case is getting sized too much, pushing the cartridge headspace back too far; allowing gas past the neck and onto the shoulder. (or the headspace on the rifle is too long).
If you have headspace comparators then try measuring a sized case vs a fired case. Id bet the headspace on the sized case is too shot. (meaning you should back your full length die out - or try neck sizing only)