are you sure 1 and 3 are corrosive, I've never seen brown lacquer Czech, and it usually is always a bxn headstampthis was a test a ran back in 2019. Number 1 & 3 were Czech surplus, 2 was the "semi" corrosive from Lever, 4 was Norinco silver box I got from Canada Ammo. I think this pic was after 1 week. Rust just starting to develop under the nail head of the semi corrosive
View attachment 1073308




















































