Soviet T-64 Main Battle Tank
The T-64 first came into service in 1966. Original versions of the tank were shipped with a 115mm D-68 gun. Later upgrades changed this over to the 125mm 2A46 gun from 1969 onwards.
DU APFSDS rounds were produced for both calibres, the 3UBM-13 at 115mm and the 3VBM-13 at 125mm. The 3BK-17 HEAT-FS round is also available at the 125mm calibre. Various other non-DU rounds are available at both calibres as well.
There are thought to be only 100 T-64s left in Russian service, but that around 4,000 are kept in storage. It seems likely that the armed forces of ex-Soviet states are still equipped with Soviet era ammunition for tank forces, which may include DU rounds.