Army type 100 selective instantaneous or delay mortar fuze, with special adapter.

When the latter fuze is employed, the Navy gaine well in the charge is filled with a picric pellet, recessed for an Army gaine.

Motor:

Weight of filled motor: 571.3 pounds.

Weight empty: 269.0 pounds.

Length of motor: 27.0 inches.

Diameter at bearing surfaces: 17.75 inches (45 cm).

Six tapered nozzles are offset 18.5° from the longitudinal axis of the motor.

Propellant:

39 grains (15.25- by 2.31- by 0.41-inch perforation) of a double-base smokeless powder, weighting a total of 131.5 pounds and code 240 Special DT6.

The grains are green and red in color.

Ignition mechanism:

Igniter: Percussion primer.

Ignition charge (black powder in silk pad): 83.0 grams.

Color and markings:

Maroon over all, with a green nose.

An Arabic number is stenciled in white on the nose. A label, carrying propellant data, is fixed to the base of the motor.

Launcher:

A crudely manufactured, wooden, trough-type launcher has been recovered for use with this ammunition.

Remarks: A variation of this round, incorporating modified coupling and base plug, has been recovered. The nose of the modified round is threaded to receive the fuze directly, whereas the nose of the original model carried an adapter welded into place. Although the internal dimensions of the modified round are identical to the first recovered speci-men, the former weighs only 1,466 pounds.

Figure 425 – 45-cm High-Explosive Spin-Stabilized Rocket.