I shot up some 50 year old .22LR ammo last June as part of a longevity test I am running. It fired perfectly. The 51 year test will be coming up soon enough.

This started when my father bought me 10,000 rounds of Federal High-Velocity .22LR ammo for my birthday in 1963. The BEST. BIRTHDAY GIFT. EVER. I shot a box (along with a box I bought with my newspaper money) each weekend from then until I went away to college. I still had a few bricks of ammo left when I went away to college and stored it in a .30cal ammo box in my parents basement on a shelf.

About 25 or 30 years later (after I finished college, started a career, got married and had our first kid), my mother handed me the .30cal ammo box and said, "I think these are yours." It was the ammo I stored away years before.

At first I thought I would shoot it up quick, before it went bad, but then I decided that it would make a great long term test. I started shooting up a box every year on my birthday. After a while I realized that I was using them up too quickly. I started shooting up a half box each birthday. I am down to my last 4 or 5 boxes of the 1963 ammo, so the test will wrap up in a few years, but I might be able to make it last for 60 years.

BTW, in that time, I have never had any of the 1963 cartridges fail to fire, misfire, hangfire, or do anything else bad. Because they were stored in a sealed ammo box, there is no sign of corrosion, discoloration, or anything else on them. They still look brand new and they act that way. Even .22LR ammo can last longer than most people believe when it is will stored properly.