A Tungsten slug is a type of ammunition used by certain Terran militia capital ships.
Composed of the element tungsten and possibly other heavy metals, the slug is made for its high heat resilience and lower cost to manufacture. As tungsten is not as radioactive as uranium, it has an added benefit of not being confiscated by major governments looking for nuclear material.
When launched at hypersonic speeds, a tungsten slug can reach similar stopping power to a small nuclear warhead. This force is also strong enough to penetrate or where down virtually all forms of energy shielding known to terran and Protoss kind.