Paper or plastic?
Edit: Sorry, I couldn’t resist. A few years ago, I shot up several cases of Winchester Super X labeled, “All New Plastic”. I’ve also shot paper shells that predate 1962. As with any ammo, I’m sure it depends on the way it was stored. If the boxes are clean and the shell cases aren’t split or bulged, it’s probably fine.
The best way to tell if it’s good is to shoot some.
I'm thinking about buying, i.e., stocking up if I find it cheap enough. I don't want to lay in a ten year supply and have it go bad in three years.