Offensive Mk IIIA1 and Mk IIIA2; also Fuzes M6 and M204A1

Over-all length, inches

5.35

Diameter, inches

Color

Fuze

Delay, seconds

4.5

Description: The Offensive Grenade Mk IIIA2 consists of a cylindrical pressed-fiber body and a charge of pressed TNT. The head contains a threaded fuze hole which is sealed by a waterproof paper disc.

It is fuzed with Detonating Fuze M206A1, which has a delay varying between 4.3 to 4.8 seconds. The fuze consists of a threaded metal body which contains the primer, de-lay element, and detonator, and to which a spring-driven striker is attached. The striker is restrained by the safety lever, which hooks over the lip of the body and passes across the head of the body, over the striker, and down the side of the grenade. The lever is held in place during shipping and handling by a split safety pin which passes through the safety lever, through the fuze body, and over the striker, to protude on the other side, where it is spread so that a pull of between 10 and 30 pounds is required to withdraw it. This fuze is distinguished from igniting fuzes by the red sealing compound, instead of green, used to seal the detonator into the fuze.

Operation: When the safety pin is removed preparatiry to throwing, the lever is held in place by the hand holding the grenade. When the grenade is thrown, the lever is re-leased. The striker, driven by its spring, throws off the lever and rotates about its pivot to strike the primer. The primer ignites the delay element, which takes about 4.5 seconds to burn through to the detonator.

The explosion of the detonator sets off the main charge, producing a blast effect. This blast is not effective against personnel except at very short ranges or in enclosed spaces.

Earlier models: The Offensive Grenade Mk IIIA1 differs from the Mk IIIA2 in that the ends of the grenade body are of sheet metal and the grenade weighs 0.875 pound fuzed. The Mk III had metal ends and contained only 0.27 pound of TNT. It was shipped with a wooden plug in the fuze well. The M6A1, M6A2, and the M6A3 models of this fuze may be encountered. These modifications have been declared unsafe for use and should be des-troyed.

Remarks: The Hand Grenade Mk IIIA2 has been taken out of production, but large quantities of them still exist.

Figure 223. Offensive Grenade Mk IIIA1 (right) and Mk IIIA2 (left)