Anyway, about reloading ammo...
How many times can you make a tiny explosion in a small metal casing before it wears out and you'd better not use it any more? Does it show visible signs that indicate it should be retired, or is it a more hidden metal fatigue and you just have to keep count of how many times this batch has been reused?
YES..... brass is flexible.... but it "work-hardens".... the chamber in a firearm is slightly larger than a cartridge (to ensure smooth feeding, standards are set by SAAMI) When the cartridge is fired, the brass expands to fit snugly in the chamber, then "relaxes" just slightly so that it can be extracted....
in order to fire it again, you must remove the used primer, and run the brass case up into a metal die, which squeezes the brass case back down to the correct size. Insert a new primer, add the proper charge of powder, and push a new bullet down into the case. Voila! (or viola, if you're from the south, like me....) It is ready to be fired again.
Depending on how much the brass expands and gets squeezed back down, it begins to lose its flexibility, and can then develop splits, or cracks...
at that point, toss 'em.... I have had some cases that I have reloaded 8-10 times.... and I've had some that developed splits after reloading just a couple of times. It mostly depends on the difference between your firearm's chamber and the cartridge.
To give you an idea of brass flexibility, there is such a thing as "fireforming" a brass case. For example, the .22 Hornet (ask me how I know
) If you want to fire it in a .22 K Hornet, you simply put the regular Hornet cartridge in the chamber and fire it. It blows out the case to fit the K Hornet.... it starts out looking like the one on the right, and after firing, it looks like the one on the left.... that's how flexible brass is...