The cylindrical body of the grenade tapers near the base and head, is grooved for frag-mentation and contains a 2-oz. bursting charge of T.N.T. The striker, forming part of the igniter set, protrudes from the head of the body and is covered by a brass cap secured by a safety pin. The igniter set is of the time type with a delay of approximately 4.5 se-conds and is initiated by a blow immediately before throwing. The grenade is 3.78 inches in length, has a maximum diameter of 1.97 inches and has a filled weight of approximately 1 lb. The grenade is marked at the head with a red disc surrounded by a black circle.

The body is of cast iron with a cup-shaped interior and is screw-threaded internally at the mouth to receive the closing plug. The bursting charge has a central cavity throug-hout its length to receive the detonator and igniter set and is topped by a washer before the insertion of the closing plug. The central cavity is provided with a liner which con-tains a wad at its base end for the detonator, while its front end fits into a central hole in the underside of the closing plug.

The detonator consists of a cylindrical shell which is solid at the base, lightly closed at the head, and contains an initiating composition of which details are not yet available. A perforated steel disc is positioned between the detonator and the igniter set.

From the incomplete information and the sketches at present available, the igniter set consists of a brass body fitted with the striker, a percussion cap and a delay filling, and a container with a perforated filling which is fitted below the body.

The brass body is screwthreaded for insertion in the closing plug and is cannelured near the top to receive a similar cannelure formed in the safety cap. Above the cannelure two holes are formed for the insertion of the safety pin. A recess is formed in the head of the body to receive the striker assembly, which consists of a protruding pellet with a screw-ed needle and supported by a helical spring and the safety pin. At the base of the recess a percussion cap is fitted over a channel filled with a dely composition which extends thrown the body and is provided with radial channel just below the cap for the escape of pressure.

The brass cap safety cap is split and cannelured for assembly and functioning and is per-forated to coincide with the body for the insertion of the safety pin.

The container below the body serves as a priming to amplify the ignition from the delay filling to bring about the initiation of the detonator. Details of the filling are not available.

After removing the safety pin the safety cap is given a sharp blow on the head before throwing the grenade. The blow forces the cap down over the igniter body and drives the needle into the percussion cap. The flash produced by the cap filling ignites the de-lay filling, which ignites the composition in the radial vent, and with the pressure set up by the combustion escaping through the vent, the delay composition burns steadily through to the priming composition. The ignition of the priming composition brings about the initiation of the detonator, which in turn detonates the bursting charge.