OVERVIEW: 125mm APFSDS-T (Armor-Piercing Fin-Stabilized Discarding Sabot – Tracer) ammunition is a high-velocity kinetic energy round designed to penetrate modern armored threats, including main battle tanks. It is optimized for direct-fire engagements at long range, relying on speed and dense penetrator materials to defeat enemy armor.

DETAILS: These rounds consist of a sub-caliber, long-rod penetrator—usually made from tungsten alloy or depleted uranium—housed within a lightweight sabot. Upon firing, the sabot is discarded, and the fin-stabilized rod continues toward the target at velocities around 1,700–1,800 m/s. The penetrator defeats armor using kinetic energy rather than explosive force, making it highly effective against modern tank armor. Variants differ in penetrator length, material, and muzzle velocity, and are compatible with a variety of 125mm smoothbore guns, though performance improves with higher-pressure guns like the 2A46M-5 or 2A82-1M.

ROLE SUMMARY:
Category: Tank Gun Ammunition
Primary Use: Anti-armor
Function: Kinetic energy armor penetration
Strong Against: Main battle tanks, armored fighting vehicles, hardened vehicle components
Weak Against: Infantry, soft targets, defiladed positions, vehicles equipped with APS or spaced armor traps
Platform: MBTs equipped with 125mm smoothbore guns
Integration: Compatible with 2A46, 2A46M, and 2A82 series tank guns

SOURCE:
Janes Ammunition Handbook
https://en.wikipedia.org/wiki/125_mm_smoothbore_ammunition