Ammo storage and age

[Mayor McRifle]

[onelonehorseman]

Properly stored, ammo can last many decades.

+1

I have no issue shooting WW2 vintage surplus if it looks decent.

[russ69]

From my own experience:

Store ammo indoors.

Well packaged centerfire ammo with copper jacketed bullets will last a lifetime.

Exposed lead bullets will start to corrode in about 20 years depending on the brand.

[XCC_RIDER]

Not soft crud, hard as a rock and it can't simply be wiped off. I tried chipping some off with my (very hard) fingernail and I couldn't get any off at all.
I guess I could use a scotch Brite pad or sand paper to remove it, but why? It's only 50 rounds out of the 12k I own so it's not a big loss.
I "forgot" it at the range so I'm sure someone who has more patience than I do will clean them up.
Or maybe not...

[RestrictedColt]

I've shot nastier looking stuff than that, but they didn't have a hard crust that kept them from chambering. My friend gave me a bunch of .22 and 12ga that he found in his garage while cleaning up after a flood and it all looked horrible....and it all shot just fine. It was stacked on the floor in nothing but their factory paper/cardboard boxes. Some of the super corroded 12ga. I cut apart and used the components to play around.

On the flip side there have been powders that were unstable and decomposed; sometimes becoming a dud, sometimes a kaboom, sometimes going off spontaneously, but that's all pretty rare. Primers can go bad and give hang fires or failures to fire.

Other than the Russian Mil-Surp stuff I've bought I don't have any old ammo because I shoot it before it ages.