Wet Shot vhells?
Much good advice here.
But let me tell you of my experience.
1941-42, father bought a Win Mod 12, 12 gauge, 32" full choke and a case of Imperial roll crimped cardboard hulled #2 & 4 for duck hunting in Rondeau Bay, off Lake Erie. He stored the case in the basement fruit cellar, an old house. He left home, I used them on weekly jack rabbit drives around where Kent, Lampton amd Middlesex counties met, usuall at least 70 locals "driving" a block. So, I used the pole jumper and rolled a few but I soon found that the shells were tight.
What to do? I took the shells out of their boxes, laid them on the old natural gas oven racks and carefully put the heat to them. Drying them did not reduce the swelling in the cardboard, nada. (My mother trusted me!)
So... I borrowed a neighbour's old 12 hammer double, probably damascus barrels, and continued hunting with Canucks for quail and cotton tails.
So, plastic hulls, well sealed, no problem. As for rust, well, as someone said, use then soon. and don't worry.
Now, if you want to know what I hunted with in 1944 when the 12 gauge shells ran out, you must ask me.
