I have a 20 MM Japanese AP projectile with a thin green band over a thin white band mid way down on the projectile. Have been told 2 different things. One person said it means its a hard steel AP projectile and another said the green means "Tracer" and the white means "armor piecing". (while the color "red" means "self-destruct" on a anti-air craft round). If it's the former ie. hard steel, why would the Japanese make an AP projectile that wasn't hard steel? Doesn't make sense to have a soft steel AP projectile does it? Hope its not to confusing the way I asked it. Any infomation appreciated.