US Cartridge, 120mm APFSDS-T, M829A3
The M829A3 cartridge is a Kinetic Energy (KE), armor piercing, fin stabilized, discarding sabot, fixed round with tracer (APFSDS-T). This antitank round is intended for use in the M256 smooth bore gun and is designed to provide terminal effectiveness over the M829A2 cartridge.
The M829A3 is a U.S. design/developed 120mm APFSDS-T cartridge. The complete round contains a propulsion/ignition system and inert projectile which is similar to the M829A2. The propulsion/ignition system consists of combustible cartridge case with a metal cartridge case base, the RPD-380 propellant consisting of 19-perforated stick, 7-perforated stick, and 43 perforated hexagonal stick, and M123A1 electric primer containing black powder base charge. The subprojectile assembly consists of depleted uranium (DU) penetrator with steel windshield fitted to the front and a six bladed aluminum fin and tracer assembly fitted to the rear. The projectile consists of the subprojectile combined with a composite material sabot, nylon obturator, rear retaining ring and a molded JRTV seal. The sabot is composed of three 120 degree non-interchangeable segments with internal grooves matching those on the outer surface of the penetrator. The sabot has a silicone rubber (JRTV) seal at the rear to prevent leakage of propellant gases and a front ring to prevent sabot splitting upon muzzle exit. A nylon obturator is used to prevent propellant gases from leaking around the outside of the sabot.