Cartridge, 105 mm: HC, M84

aluminium (M84A1) spacers; the total weight of HC is 5.57 kg. The forward end of the shell body is connected to the nose fuze cavity by a flash channel with a recess for a black powder burster charge at the base of the channel. The smoke containers are held in position by a baseplate and a PVC locking ring screwed home against it. The joint between the baseplate and the shell body is sealed by a rubber ring. In operation, the nose-mounted M565 time fuze functions at the selected time after firing; the MTSQ M577 may also be utilised. As the fuze functions the resultant flash ignites the black powder burster charge at the end of the flash channel. The internal pressure ruptures the PVC locking ring and forces off the baseplate, also ejecting the three smoke containers from the shell body. The cartridge case contains the M67 propelling charge. This consists of seven M1 dualgran propellant increments packed in individually numbered cloth bags threaded together in numerical order on a length of silk or acrylic twine. Before loading, the required increments are arranged inside the case with the No 1 increment, the base charge, at the bottom and the No 7 increment located towards the case mouth. The other increments are arranged around the walls of the case and around the primer tube. Charge 1 is the base charge consisting of 238.42 g of propellant M1 (small size). Charge 2 consists of Charge 1 plus a 41.11 g increment of propellant M1 (small size). Nominal charge weight is 279.53 g. Charge 3 consists of Charge 2 plus a 70.87 g increment of propellant M1 (large size). Nominal charge weight is 350.4 g. Charge 4 consists of Charge 3 plus a 96.39 g increment of propellant M1 (large size). Nominal charge weight is 446.79 g.