Document in pdf-format. – 6 p. MACS is two different solid propellant charges which provide a complete zoning solution for 155mm artillery applications by using multiples of a basic module. MACS is optimally designed for Crusader, the next generation in field artillery, while maintaining backward compatibility with currently fielded howitzer systems (i.e., M109A6 Paladin, M198 towed, etc.). MACS has many benefits associated with replacing the currently fielded four-charge system with its more advanced two-charge design. MACS consists of the XM231 propelling charge and the XM232 propelling charge. The XM231 module is used at lower zones (1 or 2 increments at a time) while the XM232 module is used at higher zones (3, 4, 5, or 6 increments at a time). See a comparison of MACS zones to comparable zones of currently fielded charges. Both the XM231 and XM232 are based on the classical Unicharge design, i.e., bi-directional center core ignition, granular propellant contained in a rigid combustible case, etc.; however, the XM231 and XM232 have design differences. All XM231 modules are identical allowing them to be interchangeable (likewise with the XM232). The design features allow MACS modules to be both manually and automatically handled, and to meet future.