I bet they are still good to go. I am sure if you looked at the powder you would know if it's not good. But I would only use in an emergency powder shortage.. lol.. Because they are to awesome to use, I'd keep them on a shelf in my reloading room for my buddies to drool over!!
Those are some really cool old powder cans .As far as the powder in them goes should still be good . You should be able to tell by the smell if it's bad it'll be very rancid if it's bad