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One other thing to look for in bottleneck rifle cartridges is incipient head separation. The classic sign is a bright ring in the case wall, between the extractor goove and the max bulge in the case wall (pretty much at the bulge, called the "pressure ring"). If you have a rear locking bolt or a break-open gun, the brass is going to stretch, and in a strong front-locking bolt gun, it can still stretch if your sizing die bumps the shoulder back too far.
If you are annealing case mouths to prolong their life, then head separation becomes more likely. (This is especially true if you do not protect the case wall back by the head properly when you anneal, thus making it too soft.)
One way to monitor the effects of case wall stretch is to use a stiff piece of wire with a 90° bend in it to feel the inside of the case. If you can feel a ring shaped depression on the inside, down near the web, then you are thinning the case there, and it will eventually separate if you keep shooting it long enough. How far you can go before scrapping the case is hard to judge by the "feel" method. I have sectioned a few cases that have a groove I can feel to see how thin they have become. This has allowed me to "calibrate" myself to feel for thinning that is about as far as I personally want to push a case.
SL1
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