I discovered some 22lr ammo from back around 1998 or 1999. 4 types of rounds were stored together. Remington thunderbolt. Remington viper (now discontinued). Winchester copper plated round nose. Winchester copper players hollow point. The cheap thunderbolt was the worst. The corrosion bloom is enough to make it difficult to chamber rounds. The viper did well with a little corrosion. The winchester copper plated which also has a waxy coating on the bullet did the best, no corrosion. No ringers so far. I'm going to burn up the old thunderbolt first.
Why not run them through a tumbler ? Depending on the media, tumblers are great for gently cleaning up things .
