The use of depleted uranium munitions has been fiercely debated, with opponents like the International Coalition to Ban Uranium Weapons saying there are dangerous health risks from ingesting or inhaling depleted uranium dust, including cancers and birth defects.
Because of the uranium bullets are denser and heavier than the lead bullets and you can use the uranium bullets on certain types of aircraft and other weapons systems to shred through medium to heavy armor that could not be penetrated with a lead bullet. TLDR this will be used as a force multiplier.