Just a note about DU (staballoy) rounds here in the U.S. The 20mm Davey Crockett spotter projectile has a DU body that was loaded with explosive. It was designed to make an impressive flash on impact. It isn't really an AP round, as it is nose-fuzed HE. The Davey Crockett projo is usually a plum purple, the color of oxidized DU. It is also heavy to the touch, like tungsten. Additionally, the improved LAW is reputed to have its shaped charge cone made from staballoy. I don't know how these would be classified in the U.K.