I inherited a bunch of older (10-15 years?) ammo from a guy who sold all his guns. He kept them in a non-waterproof shed, so a lot of it is rusty around the rims and primers. I am talking about mainly 9mm and 12ga shotgun ammo. Can I shoot this stuff, or should I toss it? I heard about people firing ammo that sat in sunken submarines for 60 years, but I don't want to have an accident