Ok been reloading small batches to 25 yrs. New to tumbling brass. Got a M1 tumbler cob media. Friend gives me some old rifle brass, been sitting some years. Went into the tumbler with orange "corrosion" spots on some of it. Some of these spots are like just under 1 sq. centimeter so kinda big. Some cases are just freckled with it. Came out after 3 hr. tumble with same corrosion spots. So toss the bad ones? No good? Thanks!