Have you checked the water capacity of the nosler brass. Then compared it to a different brand?
That's a good point. Checking the water capacity or at least just weighing the empty cases compared to a different brand should shed some light on that.
Another consideration is that your Nosler brass might be a bit on the soft side; I encountered that in a different cartridge with their brass.
I'd suggest trying the same load again, but with different primers (because of the known WLR issue) and a different brand of brass. Do the ejector marks go away?
