Filling: Hexachlorethane, 56.2 percent; zinc, metallic, 27.6 percent; zinc chloride, 2.9 percent; zinc oxide, 13.4 percent.

Description: This grenade is used with a special adapter which fits over the end of the rifle barrel. It is painted silver and thoroughly waterproofed with coats of heavy lacquer and paraffin.

The nose is of No. 23 gage B. and X. tin plate with rolled threads to fit those on the body of the grenade. Soft iron wire is wrapped in the thread groove and soldered in place, presumably to aid in sealing the joint. The body proper is rolled from No. 23 gage B. and X. tin plate and is soldered along one longitudinal seam. Rolled threads are provi-ded at each end to fit the threads on the nose and base.

The base is stamped from No. 18 gage B. and S. sheet steel and is screwed onto the body by means of rolled threads. Soft iron wire is wrapped and soldered into these thread grooves. The base is partially filled with plastic which has a threaded hole half filled with solder. The bottom plate is held in place by a small screw imbedded in the sol-der. The igniter pellet is encased in a thin walled brass container which is supported by tin plate screwed and soldered onto the body.

The four smoke ports are placed at 90° intervals around the base and are covered with light sheet metal disc which are held in place by waterproof cement covered with pa-raffin. There are three flash ports, spaced at 120° intervals, in the bottom of the base.

The grenade tube is made of No. 18 gage B. and S. seamless steel tubing and the upper end is threaded to fit the small end of the base. The threaded joint is wrapped with ad-hesive tape. The tube is sealed with a paraffin impregnated cardboard disc attached to 9 inches of heavy twine. The four fins are soldered to, and are equally spaced around the tube and are of No. 24 B. and X. tin plate.

The motive force and primary ignition are furnished by a standard .256 caliber Japanese rifle cartridge loaded with 1.927 grams of powder and fitted with a wood pellet. This cartridge is wrapped in paper and stored in the grenade tube.

Operation: The rifle cardridge is removed from the grenade tube and inserted in the rifle. The grenade is placed over the spigot adapter. When the rifle is fired, the gases from the cartridge propel the grenade and also pass through the flash ports to initiate the igniter pellet which in turn ignites the smoke mixture. Smoke is then emitted through the emis-sion holes.

Figure 184 – Smoke Rifle Grenade.