I still have ammo that was bought back in the 1960's and 70's for my rifles and shotguns that is just fine.
Just keep all of your ammo in sealed containers like steel ammo boxes or vacuum sealed bags,and it will last for a very long time.

I also have a bunch of Wolf 223 ammo that I bought in the mid 90's that is still sealed in the cases that shoots fine,but it has always been stored in a controlled environment.