Yes, wet
You can order an old whiskey barrel or wine barrel.
I have this 5 gallon glass jug I could use as a FF container
Old rain barrels are available and you can even order them online.
They usually need conditioning to get them water tight. This one was used as a rain barrel.
http://www.ebay.com/sch/i.html?_nkw=old+wooden+barrels
I like the wine barrel idea -- they'd have to be pretty "safe" for feed storage considering they've had wine in them. I live in Oregon's Wine Country ... plenty of wine barrels are available. They aren't super cheep, but they'd be ... sturdy ... for keeping the feed out in the chicken shed during appropriate weather and would hold plenty of feed.
How would you suggest arranging the top of the barrel?