The shell is similar to the H.E./T. (S.D.) streamlined type (Fig. 27), but has a driving band of sintered iron. The 3.7 grain self-destroying pellet consists of irrugular grains of ungraphited chopped propellant and is pressed into the cavity in the base of the high explosive/incendiary bursting charge pellet. The bursting charge pellet weighs approxima-tely 105 grains and consists of 71 per cent P.E.T.N./Wax and 29 per cent of aluminium. The aluminium is mixed in with the H.E. in the form of irregular flakes of thin foil, ranging in size from 5 x 4 mm (maximum) to 1.4 x 0.5 mm (minimum). The pellet is held lightly in compression in the shell by paper washers under the fuze.

The steel shell is fitted with a copper driving band and is cannelure pressumably for the attachment of the cartridge case, although rounds examined have not had the case in-dented into the cannelure. The pyramid diamond hardness figure for the point of the shell is 982. This figure decreases gradually to 527 to the base. The cavity in the interior is of the small type characteristic of piercing shell and contains 46 grains of yellow phospho-rus. The charging is sealed by a lead disc supported by a steel disc, both being secured in position by the solid end of the steel tracer plug. The tracer plug is in the form of a cup, screw-threaded externally to screw into the shell and lined internally with a copper-plated steel tube which contains the pressed tracing and priming compositions. The base end of the tube is closed by a celluloid disc secured with a varnish.

The priming composition consists of barium peroxide and magnesium with a binding mate-rial. The tracing composition includes barium nitrate, magnesium, sodium oxalate, French chalk and resinous matter. The trace is pale green and burns statically for 2.4 seconds.

Fig 28

GERMAN 2 CM, SOLOTHURN, A.P./I./T. SHELL

This projectile is identical with the A.P./I./T. shell except that the cavity contains a 55-grain filling consisting of sulphur and fine sand. The tracer fitment is as described for the A.P./I./T. shell.

At 100 yards and normal impact, the projectile will penetrate with certainty up to at least 40-mm armour plate, it may penetrate 50-mm plate.

Fig. 29

GERMAN 2 CM SOLOTHURN A.P./T.
SULPHUR FILLED SHELL

This red-tipped shell (see table of markings) is similar to the previous type but has three steel discs inserted between the tracer plug and the sulphur pellet. The pellet weighs 52 grains and consists of 70 per cent of sulphur and 30 per cent of sand.

The trace is bright and changes from green to red.