Cartridge Millimeter Smoke W M With Fuze Multioption Ma

Type Classification: TC-STD Use:

This cartridge is a smoke, white phosphorous (WP) round developed for use in the M120 and M121 120mm mortar system. It is intended for use as an incendiary device and to produce a screen.


The complete round consists of a fuze, propellant charge, fin assembly, ignition cartridge and shell body. The shell body, made of wrought carbon steel is loaded with WP filler. The ignition cartridge has a percussion primer and is assembled tot he end of the fin assembly. The propellant charge is contained in four horse-shoe-shaped felt fiber containers and assembled around the fin assembly shaft.


When the cartridge is dropped down the mortar tube, the firing pin at the bottom of the tube initiates the percussion primer and charge in the ignition cartridge. The charge in the ignition flashes through the holes in the shaft of the fin assembly and ignites the propelling charge. The gases from the burning propellant expand and propel the cartridge out of the mortar tube. The fuze functions on proximity burst and the booster ignites the burster charge in the center part of the projectile body. The burster charge fragments the projectile body and disperses 144 felt wedges impregnated with WP, which burns immediately on contact with air. The wedges burn for approximately 2 minutes, creating a smoke that is twice as effective as the 4.2-inch, M328A1.

Tabulated Data: Complete Round:

Weight 31.2 lb

Body material Wrought carbon steel

Color Light green w/yellow band and light red markings.

Filler and weight. . . WP felt wedges, 5.28 lb (2400 g)


Ignition cartridge . M981

Propellant charge . M230

Fin assembly M31

Fuze Multi-option, M734A1

Burster M86

Temperature Limits: Firing;

Lower limit -50oF (-45.6oC)

Upper limit +145oF (+62.8oC)


Lower limit -60oF (-51.1oC)

Upper limit +160oF (-71.1oC)

*Packing 1 round per fiber container; 2 fiber containers per metal container

Fiber container:

Drawing number . 12577551 Metal container:

Drawing number. . 12577570

*NOTE: See DOD Consolidated Ammunition

Catalog for complete packing data including NSNs.

Shipping and Storage Data:

UNO serial number 0245

Quantity-distance class. . .(08) 1.2 Storage compatibility groupH

DOT shipping class A




Store and transport WP rounds at temperatures below 111.4oF (melting point of WP). If impractical, store rounds on bases so that if WP melts, it will resolidify with void space in normal position in the nose of the cartridge. Erratic performance may occur if voids exist inside of WP filler.

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