How does the vendor who sold them control shipping conditions in a sealed cardboard case? Gimme a break. I put it on you, who loaded your gun with shells that had corroded heads. Do a better job of paying attention to detail and look at what you put into your gun before loading it. Even by your own admission the shells with out corroded heads ran fine, yet you pull no punches disparaging the entire line of Italian made, Cheddite hulled shells that work fine for 99% of the people whove used them.
Corroded bases on these newer steel based hulls that are brass or zinc washed is not uncommon. Check em before you load em.