The use of depleted uranium in projectile weapons has been featured frequently in the news recently. Question asked by Rob War is a mucky business at the best of times and especially so when it comes to depleted uranium, which is actually a waste product of the nuclear industry. It just happens to pack a punch when attached to the front of an anti-tank missile. Depleted uranium is used on anti-tank ammunition for a number of reasons. When you enter the world of high-speed collisions strange things happen.
Hardened steel can shatter like glass, while other metals simply flatten against the armour plate.
The trick is to concentrate as much force into as small an area as possible. Depleted uranium is great for this as it is almost twice as dense as lead, packing a big punch. Depleted uranium also burns at the point of impact, so the projectile self-sharpens as it goes through the tank armour. In contrast, tungsten, the main alternative to depleted uranium, deforms and mushrooms as it goes through metal making the projectile progressively blunter. The final advantage of using depleted uranium is, as always, cost.