I have a 300 saum, that I recently purchased some Nosler Brass for. Prior to that I was using the Rem. brass, but when I found out that Nosler was making brass for it, I bought some. I love the quality of it and I don't have to do hardly anything to it as far as primer holes or chamfering, or anything. The pockets are nearly perfectly square also. But what I do notice is that after about 3-4 firings, when I resize, the expander ball seems to be very tight on removal, no matter how much lube I use. I use and have always used Imperial Lube. The remington brass does not seem to do this, but it does seem to grow a little more than the Nosler brass. Could this be work hardening? (Note, I do full length resize, just off of the shoulder.) Any thoughts?