DESCRIPTION. – This grenade consists of a die cast aluminum container which encases a steel tube containing the explosive. The fuze screws to the steel tube and the tube and aluminum container are secured by knurling and indents. The propellant charge is contained in a cup which has a push fit to the grenade with 10 holes in the cup to lead the gases to the base of the grenade. (See fig. 312.)

The grenade has five grooves making onequarter turn in the length of the projectile, grooved on the aluminum body. The steel liner is threaded internally to take a nose per-cussion fuze. The explosive filler consists of two penthrite wax pellets separated by cardboard discs.

The fuze is a direct action type and is fitted with a protruding striker head. The striker is held away from the primer by six steel balls which rest in groove in the striker and on a platform of the fuze. These balls are kept in position by a steel collar which is supported on three aluminum pins. There is also a creep spring between the striker and the primer. Beneath the primer there is a gaine contained in an aluminum case and consisting of lead azide and lead styphnate in the upper part and PETN in the lower part. Between the gaine and the main filling there is an empty air space.

The discharge cup is a push fit with the base of the grenade which is turned down to fit into the cup. The cup has in its base a lead syphnate primer contained in a brass holder. Forward of the cap is the propelling charge of black powder and 10 holes to lead the ga-ses to the base of the grenade.

OPERATION. On firing, the propelling charge propels the grenade and it rotates because of the rifling on the body. On setback the collar in the fuze moves back crushing the alu-minum pins and because of centrifugal force the balls then fly outward, freeing the stri-ker which is kept off the primer by the creep spring. On impact, the striker impinges the primer setting off the gaine and main filler.

Figure 312 – H.E. Cartridge for 27-mm Grenade Pistol