Shotgun Ammo

[fishfighter]

how do you guys keep from wasting your shotgun ammo, i had several boxes that i had to dispose of cause of corrosion and rust, has anyone else had this issue, had it in an orange "dry" box, it was all winchester brand mostly high brass lead shot and a few steel, is this a box issue or a shell brand issue, i like to keep a few boxes on hand, any info on what i can do to prevent this from happening is appreciated