US Cartridge, 81mm TP, M879
This cartridge is a full range training round for use in the M252 improved 81mm mortar system.
This cartridge consists of a PD (practice) fuze, an inert loaded projectile body, fin assembly, four propellant increments, obturating ring and an ignition cartridge (with integral primer). The cartridge with the M751, PD fuze resembles the 81mm M821 HE cartridge. These practice cartridges are ballistic matches to the HE cartridges and produce a similar signature (flash, audible sound, and smoke cloud) upon impact on the ground.
Collaborative Ordnance Data Repository