Try measuring neck thickness.
I've had some brass (think it was PPV) that had a beefier neck brass, this was both in 6.5 and 223.
When you resize the depriming pin usually has a ball that gets pulled back through the neck. With enough friction it will pull the shoulder out a bit and cause harder to chamber rounds. You could try some graphite lube on the necks (comes in a small container with a bunch of little beads), that worked for me.
I've had some brass (think it was PPV) that had a beefier neck brass, this was both in 6.5 and 223.
When you resize the depriming pin usually has a ball that gets pulled back through the neck. With enough friction it will pull the shoulder out a bit and cause harder to chamber rounds. You could try some graphite lube on the necks (comes in a small container with a bunch of little beads), that worked for me.
