My theory is you cannot have too much. Ammunition might become more valuable than money and you could store thousands of rounds in a small space.
You might be able to barter for items using popular ammunition that no amount of currency or coin would buy.
It might be a great idea to buy and store ammo even if you don't own a firearm in the particular caliber. Popular calibers are .22, .223, .38 Special, 9MM, .45 ACP, 7.62 x 39MM and the nearly universal 12 Gauge shotgun shells.
Thanks. I've done that.
I'm working on coffee and chocolate presently. (Yes, really!)
What will happen if shipping breaks down...No coffee!!