Ammo doesn’t go bad. I’ve got some “cartuchos” that came with an 1881 Argentine Mauser that work fine...
“Ammo doesn’t go bad”
From http://www.thecmp.org/ammosales.htm
WARNING
All ammunition is subject to deterioration over time.
Customers should expect that 5% to 15% of the cartridges in any can may exhibit some stages of discoloration or corrosion or other abnormalities. As with any surplus ammunition, each and every round should be carefully checked before use.
Deformed or otherwise suspect rounds should not be fired.
These cartridges are aged surplus military ammunition.
This ammunition is NOT newly-manufactured, and is sold STRICTLY
IN “AS IS” CONDITION, with no warranty expressed or implied.