They should literally last centuries as long as they're kept dry. People still fire WWII surplus, no problem. Old muzzleloaders from the 1700s have been found loaded, and have fired fine. The ingredients are stable, and the way ammunition is put together protects them.
every two months..... Ill dispose of all your old ammo for you no charge.How long can you store ammo before it needs to be replaced?
Well I was mostly referring to hollow points that I wouldn't shoot at the range