Ammunition
Most military use of depleted uranium has been as 30 mm and smaller ordnance, primarily the 30 mm PGU-14/B armour-piercing incendiary round from the GAU-8 Avenger cannon of the A-10 Thunderbolt II and M230 of the Apache Helicopter<9> used by the U.S. Air Force. 25 mm DU rounds have been used in the M242 gun mounted on the U.S. Army's Bradley Fighting Vehicle and LAV-AT. The U.S. Marine Corps uses DU in the 25 mm PGU-20 round fired by the GAU-12 Equalizer cannon of the AV-8B Harrier, and also in the 20 mm M197 gun mounted on AH-1 helicopter gunships. The US Navy's Phalanx CIWS's M61 Vulcan gatling gun used 20 mm armor-piercing penetrator rounds with discarding plastic sabots which were made using depleted uranium, later changed to tungsten.
Another use of depleted uranium is in kinetic energy penetrators anti-armor role. Kinetic energy penetrator rounds consist of a long, relatively thin penetrator surrounded by discarding sabot. Two materials lend themselves to penetrator construction: tungsten and depleted uranium, the latter in designated alloys known as staballoys. Staballoys are metal alloys of depleted uranium with a very small proportion of other metals, usually titanium or molybdenum. One formulation has a composition of 99.25% by weight of depleted uranium and 0.75% by weight of titanium. Another variant can have 3.5% by weight of titanium. Staballoys are about twice as dense as lead and are designed for use in kinetic energy penetrator armor-piercing ammunition. The US Army uses DU in an alloy with around 3.5% titanium.
http://en.wikipedia.org/wiki/Depleted_uranium#Ammunition