Modern centerfire ammunition has a very, very, long lifetime, much longer than the people who ran the machines that loaded it.
Sealed in a cartridge, modern smokeless powers do not really deteriorate, so as long as the cases are in tact, not bulged, water damaged, oil soaked, or corroded I'd say odds are it'll go bang.
It's my understanding that when stored properly, (cool and dry) modern ammunation's useful life will likely out last your great grandkid's grandkids!
/c