It is the chamber of a firearm that contains the force of firing a cartridge. The cartridge itself contributes little or nothing to containing that force. As cartridges are reloaded successively, they all experience some form of structural failure, typically a crack in the neck. At the 1st sign of failure they are discarded.
B.B.,Thank you for sharing your reloading experience and knowledge. I have never reloaded cartridges, only shotgun shells. I have shot some center fire pistols and rifles, but have never actually owned one myself. I do enjoy reading the blog regarding this topic though. I do know that one should always stick to the recipe for components. There was a very smart engineer at work that tried experimenting with powders and charges. He blew up a nice rifle, luckily he was not injured. Reloading can be dangerous if things are not done correctly, or one thinks he knows better how to reload using a different recipe. I would stay away from those fellows. ?Geo 2b1af7f3a8