As you would never use leaded fuel on your unleaded car, never use ammunition which are not proper for your gun. Serious damage, or injury can result. Also, never use ammunition which does not look the way it should look. Old rounds can not only harm your gun, they can also harm you. Do not, under any circumstances alter the rounds and especially the powder of ammunition.
Ammunition stored under proper conditions can live almost indefinitely.
However try to always use fresh ammo with your guns. Guns and drink do not mix. If you are going to use your firearm, do not drink. If you have drunk, do not use your firearm. Mind of your backstop.