Conversion of M231 (MACS) and M232 (MACS) charges

Modular charges M231 (MACS) and M232 (MACS): description and tabular data

Charge M231 (MACS), lower-zone module, charges 1 and 2

Purpose. The M231 propellant charge is the low-zone charge of the Modular Artillery Charge System (MACS) for 155 mm field guns. The charge was optimized for the Crusader field artillery system, but it is compatible with all 155 mm systems with barrels of 39 and 52 calibers. Zoning is achieved by adding modules. No more than two M231 modules may be used in a single round.

Description. The M231 charge has a green combustible nitrocellulose-based case with a coating, black stripes and black markings. Inside the case is solid granular PAP-7993 propellant.

The central ignition system with black powder and ball powder provides fast and controlled ignition at any temperature and pressure. The end igniter pouches are closed with red seals. The charge is bidirectional: it can be loaded and ignited with either end forward. Two M231 modules are packed in a green pull-out sleeve.

Function. The energy of the flash of black powder in the M82 percussion primer ignites the end igniter pouch. The flash of the end pouch ignites the ball powder in the central core, which in turn ignites the main propellant.

If a second module is used, the process is repeated. The gases expanding rapidly from the charge push the projectile out of the gun barrel at the velocity required to hit the target.

Tabular data: propellant charge M231

Temperature limits

Restriction. Do not fire more than two M231 charges per round. Do not fire M231 charges together with M232 charges.

Charge M232 (MACS), upper-zone module, charges 3–6

Purpose. The M232 propellant charge is the high-zone charge of the MACS modular system for 155 mm field guns. The charge was optimized for the Crusader system, but it is compatible with all 155 mm systems with barrels of 39 and 52 calibers.

Zoning is achieved by adding modules. In a 39-caliber barrel, no fewer than three and no more than five M232 modules may be used per round; for 52-caliber guns with a chamber volume of at least 23 litres (for example the 2S22 Bohdana), up to six modules.

Description. The M232 charge has a light-brown combustible nitrocellulose-based case with a coating and black markings. At each end there are four lugs 3.2 mm high. Inside the case is solid granular M30A1 propellant.

The central ignition system with black powder and ball powder provides fast and controlled ignition at any temperature and pressure. The end igniter pouches are closed with red seals. The charge is bidirectional: it can be loaded and ignited with either end forward. Two M231 modules are packed in a green pull-out sleeve.

Function. The energy of the flash of black powder in the M82 percussion primer ignites the end igniter pouch. The flash of the end pouch ignites the ball powder in the central core, which in turn ignites the main propellant.

If a second module is used, the process is repeated. The gases expanding rapidly from the charge push the projectile out of the gun barrel at the velocity required to hit the target.

Function. The flash of black powder in the M82 percussion primer, its energy transferred to the black powder of the end igniter pouch, ignites it. The end pouch burns and ignites the ball powder in the central core, which in turn ignites the main propellant. For subsequent modules the process is repeated. The rapidly expanding gases push the projectile out of the gun barrel at the velocity required to reach the target.

Tabular data: propellant charge M232

Temperature limits

Restriction. Do not fire fewer than three M232 charges per round. Do not fire more than five M232 charges in a gun with a 39-caliber barrel. Do not fire more than six M232 charges in a gun with a 52-caliber barrel. Do not fire M231 charges together with M232 charges.

Weight of the full MACS charge by zone (calculation)

The TM gives the weight of only one module. The weight of the charge by zone is calculated by multiplying by the number of modules (values given to two decimal places).