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So I went more in depth here. I tried some once fire RP brass. Before sizing, it chambered fine, I couldn't feel resistance. After sizing, the bolt definitely closed with more pressure. Not that bad, but definitely there. I colored that same case with a marker, and it is hard to see but there appears to be a ring right at the neck/shoulder junction. I measured the rest of the case, right below the shoulder/body junction, midway down the case, and at the bottom. All those measurements were within .001 of an unsized case. So what can I learn based off of these further developments? Need some wiser heads helping me out here. Thanks!

......the occasional hunter wielding a hopelessly inaccurate rifle, living by the fantastical rule that this cartridge can deliver the goods, regardless of shot placement or rifle accuracy. The correct term for this is minute of ego.