This fixed Q.F. round is fired from the 5 cm tank gun (short) (5 cm Kw.K.). The shell is fitted with a penetrative cap in the form of a cone with the apex cut away. The nose of the cap is shaped to form a point. The shell with its cap is painted black and stencilled in red. The cartridge case has the model number "6317 St" and the designation of the equipment "5 cm Kw.K.", stamped in the base. The following markings relating to the equipment and the weight, nature and size of the propellant charge are stencilled on the side of the case in black:– "5 cm Kw.K. 499 g. Digl.R.P. –G 0,5– (200 x 2/1)". The mark-ing "P.T. + 25° C", in-dicating a charge weight for a normal charge temperature of 25° Centigrade, is in read the base of the case. The overall length of the round is approxima-tely 16.8 inches and the weight 7 lb. 10 oz.

Armour-piercing shell fitted with penetrative cap, and filled P.E.T.N./ wax.

Base fuze, 5103* with tracer.

Case model, 6317 St.

Propellant charge of double base composition with igniter.

Primer, electric C/22.

The capped shell is fitted with an iron driving band and has two cannelure near the base for the attachment of the case. The small cavity for the bursting charge is closed at the base by the fuze. The weight of the empty shell is 4 lb. 3 oz. 13 dr.

The bursting charge, which is 50 per cent larger than that in the A.P. shell, consists of 14 dr. of P.E.T.N./wax 87/13 and has a cavity formed at the base to receive the gaine fitment on the fuze. The weight of the shell filled and fuzed is 4 lb. 8 oz. 15 dr.

The base fuze 5103* with its adapter and gaine is the same as that described for the A.P. shell in Pamphlet No. 4, pages 14 and 15. The igniferous detonator composition con-tains no fulminate but consists of:– 53.4 per cent of potassium chlorate, 34.3 per cent of antimony sulphide and 12.3 per cent of calcium silicide and glass (approximately 3 to 1 of silicide). In addition, there is a small layer of gun-powder in the base end of the deto-nator.

The tracer is screwed into the base of the fuze and is of the normal type consisting of a steel body with a steel liner and closing disc and a celluloid disc at the base. The tracing composition is pressed with a teat-ended drift in one increment of 23 grains and consists of 3.3 per cent of resinous matter (probably shellac), 47.5 per cent of barium nitrate, 22 per cent of magnesium, 0.5 per cent of iron and 26.7 per cent of silicious matter. The priming composition is pressed with a serrated drift in one increment of 20 grains and consists of 66.7 per cent of bar-ium peroxide, 12.9 per cent of barium carbonate and 20.4 per cent of magnes-ium.

The case is of the necked type and is approximately 11.4 inches in length. As indicated by the letters "St" stamped after the model number in the base, the case is of stell and is coated with brass.

The weight of the propellant charge, according to the markings, is 1 lb. 1 oz. 10 dr. and the igniter 5.5 dr. The charge is contained in a bag with an igniter bag formed at the base.

The propellant is in tubular form, the dimensions of the tubes being:– length 7.9 inches, external diameter 0.08 inches, internal diameter 0.03 inches. The composition, as found by analysis, is as follows:–

61.75 per cent

26.19 per cent

8.09 per cent

0.8 per cent

2.9 per cent

0.27 per cent

The igniter bag is marked "10 g. Nz.M.N.P. (1,5 x 1,5)". The filling consists of pale grey-green porous cylindrical grains of nitrocellulose composition. The composition contains 88 per cent of nitrocellulose (nitrogen content 13.1 per cent) and includes diphenylamine, carbamite, potassium sulphate and graphite.

The electric primer C/22 is described in Pamphlet No. 4 page 31. A new feature is the use of a blue insulating material probably consisting of vinyl polymer. Previously a yellow cel-lulose acetate composition has been used.