I do the same with my case. They stay together as a lot, and when one case show sign ( usually that slight ring precursor of case head separating ) I dump them all. No need to damage a gun or worse injure myself for a few $$ of brass. And it really suck when half a case stay in the chamber and ruin your day at the range..
Low pressure caliber, such as 45-70 ,will usually show wear at the case mouth first (split ) before anything else.never had to retire one for showing the beginning of case head separation on those.
When you have primer pocket loosening, you know your load are hot.
You know they are shot when they look like this
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