
This cartridge is a kinetic energy, armor piercing antitank round intended for use with the 120mm smooth bore M256 cannon.
The M829A1 is a U.S. design developed 120mm APFSDS-T cartridge. The complete round contains a propulsion system consisting of a metal cartridge case base with combustible sidewall, granular propellant within a containment device to prevent spillage, and M129 primer, while the projectile consists of the subprojectile and aluminum sabot. The depleted uranium penetrator is a one-piece design which is assembled into the sabot by means of buttress grooves. There is a six bladed aluminum fin with tracer assembly fitted to the rear of the subprojectile and a windshield and tip fitted to the front. The aluminum sabot is composed of three 120 degree noninterchangeable segments with internal grooves matching those on the outer surface of the penetrator. The sabot has a silicone rubber seal at the rear to prevent leakage of propellant gases.
The projectile is black with white markings.
The M829A1 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 down-bore. 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.
Primer - M129
Length, overall - 38.75 in, 984.3 mm
Cartridge, 120mm APFSDS-T, M829A2