Description
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.
Functioning
The M829A3 is loaded and fired from the M256, 120mm in the normal manner. Initiation of the electric primer ignites the propelling charge and combustible case, generating gases which drive the projectile from the gun and ignite the tracer. The silicone seal at the rear of the sabot prevents gas leakage between the sabot segments and the driving forces (gas) propelling the subprojectile downbore. Upon leaving the gun, aerodynamic forces cause the sabot to separate from the subprojectile allowing the subprojectile to continue on a true course to target while the sabot segments fall quickly to earth. Target penetration is effected strictly by the high kinetic energy of the subprojectile impacting the target.
Hazardous Components
Propellant - RPD-380
Primer - M123A1
Tracer - plug and disc assembly, PN 12525133
Physical Data
Length, overall - 38.74 in, 984 mm
See Also
Cartridge, 120mm APFSDS-T, M829A2
Source(s)
