The M1A-M compressed air delivery device is a paint marker system resembling a military crew served mortar, similar in visual impact to a standard military 81mm mortar. The marker system is a smooth bore, muzzle loading, gas/Co2 operated, manually fired, high angle-of-fire training device. The device propels a marker round (water soluble marker paint), that produces a 70+ feet in diameter fragmented area. The device is made of all steel, with a cannon of aluminum. The device is shipped in a wooden crate with flexible handles on either end, which supports field transport and storage. The device consists of three components; cannon assembly, mount and base-plate assembly, and traversing and elevation (T & E) assembly . The cannon assembly consists of a barrel assembly and Co2 expansion chamber assembly with the upper base-plate and barrel-attaching bracket, charging valves, gauges and quick release firing valve (cannon is constructed of .250 thick wall aluminum). The mount assembly consists of a functional elevation control screw, traversing control screw and the bipod leg assembly. The traversing mechanism consists of the yoke and the traversing spindle assembly and mount which provides a functional traversing and elevation sighting system to provide functional indirect fire control. The base-plate assembly consists of a 12 inch by 12 inch by .250 inch thick steel plate with ground lugs and lower base-plate and barrel attaching bracket.
Ammunition for the M1A-M crew served mortar system consists of liquid fill contained in a latex tubing bladder encased in a cardboard and urethane cast shell casing.
Rounds are impact detonated causing casualties through simulated fragmentation effects.