Full. They sit in ammo cans, sometimes for years that way. They always work. USGI, I should say.
Should also say most are Okay or other old mags. The newer D&H need to have feed lips lightly dressed with a file before I'd trust them fully loaded.
When I've stored P-mags full in cans without covers they sometimes lose a round being jostled about. Not bashing P-mags. If I need mags to withstand being run over by a tank, or dropped from an aircraft, they'll get the nod. I don't need such things, so.....
