Yes, it can, but this generally depends on storage conditions; anytime the temperature or humidity goes outside of certain ranges, the chances of misfires, hangfires and duds starts to climb, and this is part of the reason why the military keeps close track of such things. The trunk of a car is not such a great place to keep ammo, because it goes through cycles of very hot, very cold, condensation, and so on. Some police departments (who generally keep extra shotgun and sidearm ammunition in the trunk for emergencies) will usually fire that ammo off during qualifications, and replace it with fresh stuff for another year. As a general rule, keep it cool (not cold) and dry, and it will outlast you.