Originally posted by NFrameFred:
Can't add anything to the good information given about most pistol/revolver rounds given thus far, but pertaining to rifle rounds, I use a 'tool' made from a paper clip straightened and small "hook" or bend in the end of it to feel the side inside of the case from the bottom up. If you feel a 'catch' or a 'ring' it is the sign of an impending case head separation and the case should be crushed and discarded immediately. After the second or third loading, I check all my rifle shells being reloaded in that manner.
Because of everything involved, chamber variations from gun to gun, case lengths, crimp pressure, minute variances in one set of dies to the next . . . . most of the time it's a non-issue, but as with most 'accidents' it's usually a combination of a number of random factors coming together at one unfortunate time instead of a single precipitating cause. And one of the best reasons to always wear safety glasses when shooting any kind of a firearm.