APFSDS

APFSDS, or Armor-Piercing Fin-Stabilized Discarding Sabot, is a type of kinetic-energy anti-armor round used in modern main battle tanks. It relies on a dense, slender penetrator accelerated to very high velocity, encased in a larger-diameter sabot that is discarded after leaving the gun barrel. The penetrator is stabilized in flight by fins, allowing accurate firing at long ranges despite the long gun tubes of contemporary tanks.

The penetrator is a long-rod, subcaliber projectile made from very dense materials such as tungsten heavy alloys or depleted uranium, sometimes with composite or ceramic enhancements. The long-rod, fin-stabilized design concentrates kinetic energy along a narrow axis, increasing penetration against rolled homogeneous armor and other heavy defenses. Because it is a kinetic-energy round, there is no explosive warhead; penetration is achieved by crush and shear of the armor material.

APFSDS was developed in the mid- to late-20th century to surpass earlier armor-piercing rounds such as APDS. It has become the dominant form of main-gun ammunition in many modern tanks around the world, with multiple designs produced by different nations. Variants differ in penetrator material, geometry, and propulsion; some use depleted-uranium cores for higher density or specialty tungsten alloys.

Limitations include reduced effectiveness at very long ranges, against highly modern composite and reactive armors, and the need for precise gunnery and stabilization. Overall, APFSDS remains a cornerstone of modern armored warfare due to its high penetration capability and relatively low collateral effects compared to shaped-charge munitions.