If you keep them in a dry environment, they will last years (What I have found). I keep mine in the safe year round. I fill the speed loaders from the boxes in the safe and they go with me but the boxes stay in the safe. I bring the ones from the loaders back and put them into a different box and sight in with them next year. Hope that helps. The sticking together could be from moisture or just settling. I'd shoot a couple just to be sure.