Smokless powder B by analysis is a mixture of 27.71 percent N.G., 63.50 percent nitro-cellulose, 0.45 percent graphite, 0.34 percent ash, 3.81 percent ethylcentralite, 3.68 percent diphenyl formamide, and 1.30 percent volatiles. Six long sticks (34.0 cm. by 5.8 cm. by 1.05 cm. perf.) and two short sticks same diameter and perforation and 1/2 length. In some cases, one or both of the short grains have been omitted in assembly.

Ignition mechanism:

Igniter: Pull friction igniter.

Ignition charge (B.P. in two blue lacquered silk bags).

Weight of ignition charge: 0.09 pound (0.04 kg.).

Color and markings: Black over all. Head carries single yellow band at its junction with rocket motor. Weight of head and motor stenciled on each component.

Launcher: The only launcher recovered for use with this round is a single barrel-type launcher.

Remarks: A newer model of this round has been recovered, similar to the first but with the rocket motor wall diametrically reduced to 18.9 cm. (7.44 inches), giving a bourrelet effect at each end of the motor. The motor weight is correspondingly reduced to 42.43 kg. Neither the head nor the motor is interchangeable with its respective component in the older round.

Figure 295 – 20-cm High-Explosive Spin-Stabilized Rocket.