I've never had a problem storing cartridges for a year or more. I just keep them in my closet with all the other stuff my wife wishes I would put somewhere else. Seriously, I don't do anything special. I keep them in the closet. I just shot 2 boxes earlier this week that I've had for probably 2 years. They shot wonderfully! You don't need to do anything special other than keep them dry unless you just want to. Having confidence in your equipment can make all the difference when the moment of truth comes. Do whatever gives you that confidence.