The turret roof has two hatches, one for the gunner and the other for the loader. There are six road wheels each side and five track-return rollers. The mortar is probably provided with an interrupted-screw breech mechanism and a chamber detent to retain a round in place when the barrel is elevated.
Ammunition is fixed and loading is manual, although ramming is automatic.
In the indirect fire role the mortar fires high explosive, white phosphorous and smoke rounds. Mounted below the turret rear is an ammunition loading hatch and mounted on top of the hull is a device for loading ammunition from the ground directly into the fighting compartment. This allows sustained fire missions to be carried out whilst still retaining onboard ammunition supply. The 2S9 takes 30 seconds to come into action and a similar time to come out of action. When in the firing position the suspension is raised to provide a more stable firing platform.