I have about 100 30-06 brass once fired I found in a shoe box.
jeager106, your cases have head stamps , some head stamps include the year included in the head stamp, there is a chance your cases are not corrosive. If your cases are not 100+ years old, clean then, load them and then shoot.
then there are bar codes on boxes, we have no way of knowing when the cases were placed into the shoe box, again, it is not the powder that is corrosive, it is the primer, it is possible the shooter shot ammo from the 40s in the 70s. If the shooter cleaned the barrel the crises has passed.
F. Guffey