A bright shiny ring has appeared on the outside of my 256 brass which I made from new, annealled 357. I cut one off close to the ring to get a good look inside and everything looked ok. No signs of stretching or a groove. These have only been fired 2 times with 18 gr of AA1680 under a 60 gr Hornady with sm rifle cci primer. That's straight out of the AA Red Book. My brass weighed the same of factory brass. I'm getting 2800 fps from this load. No outward signs of high pressure. No head stretching, no flattened primers. Very good accuracy. What might be causing this ring? Also I have a lot of trouble when crimping with bulged shoulder that won't chamber. This, even though I use a "gentle touch"on the press handle. The rounds won't feed from the magazine into the chamber if they aren't crimped. How can I solve this?