(Figs. 16 and 17)

The cartridge is used in the 17 cm K. in Mrs.Laf. (17.25 cm gun mounted on the 21 cm high angle-mobile carriage) and consists of the case with the percussion primer of the C/12 type and the propellant charge in five sections. Only one of the sections (the Hauptkart) is contained in the case when packed, the remain-der being packed in metal cylinders. The sections provide four charges but are marked with abbreviated designations instead of the usual charge section nume-rals. These markings are also found on the packages. The designation used are as follows:–

Section 1

Section 2

Section 3

Section 4

Section 5

Charge 1

Charge 2

Sonderkart. 1 with Sonderkart 2. extending down on side. Both sec-tions in the case.

Charge 3

Vorkart. 3 loaded into the front of the chamber and followed by the Hauptkart. contained in the case.

Charge 4

Vorkart. 3 with Vorkart. 4 contained in its central tube, loaded into the front of the chamber and fol-lowed by the Hauptkart. contained in the case.

Charges 1 to 3 (inclusive) are used with the H.E. streamlined shell "Gr. 39" fuzed with the A.Z. 35 K or Dopp.Z. S/90 K fuzes. Charge 4 is used with the H.E.B.C. streamlined shell "Gr. 39 (Hb)" fuzed with the Hbgr.Z. 35 K or the Dopp.Z. S/90 K fuzes.

The case is stamped at the base with the model number 6342 and the designation of the equipment "17 cm K.Mrs.L.".

The propellant charge is of the Digl. double base type consisting basically of diethylene glycoldinitrate and nitrocellulose. The weight nature and size used in the sections, as in-dicated by the markings, are:–

The weights of the propellant charges, as stencilled on the bags vary considerably and are apparently adjusted charge weights based on the performance of the propellant lot at proof.

Fig. 16

Section 1 (Sonderkart. 1) is approximately 40 inches in length and consists of a bundle of tubular cords of propellant contained in a white cylindrical bag. The bag is choked at the front end and carries an igniter at the base. The igniter contains approximately 100 grams of Nz.Man.N.P. (1,5 x 1,5). This is the nitrocellulose powder, in the form of cylin-drical grains, normally used in German igniters.

Section 2 (Sonderkart. 2) is approximately 40 inches in length and consists of five com-paratively small bundles of tubular cord propellant contained in separate pockets formed in a white rectangular bag. The bag is swen from top to bottom with parallel rows of stitching to form the five pockets, the central pocket being the widest. In appearance the filled bag is similar to a cricketers leg pad and when required for use is assembled around one side of Sonderkart. 1 in a similar manner and inserted in the case. This sec-tion has no igniter.

Section 3 (Hauptkart.) is approximately 26 inches in length and consists of a bundle of tubular cord propellant assembled around a central propellant cylinder and contained in a white cylindrical bag. The central cylinder of propellant extends through the length of the bundle and has an external diameter of 1.4 inches. The internal diameter is 1.2 inches. An igniter containing 80 grams of Nz.N. P. (1.5 x 1.5) is stitched to the base of the bag.

Section 4 (Vorkart. 3) is approximately 27.2 inches in length and consists of a bundle of tubular cord propellant assembled around a central propellant cylinder and contained in a white cylindrical bag. The central cylinder of propellant extends through the length of the bundle and has a large cork disc, in the form of a washer, placed over its front end which protrudes from the bundle. The external and internal diameters of the cylinder, which ac-commodates Section 5 (Vorkart. 4) when the latter is used, are 2.75 inches and 2.5 in-ches respectively. The bag has an igniter containing approximately 40 grains of Nz.Man. N.P. (1.5 x 1.5). The forward part is marked "VORN" to indicate that the section should be loaded with this end to the front.

Section 5 (Vorkart. 4) is approximately 26 inches in length and consists of a small bundle of tubular cord propellant contained in a white cylindrical bag of comparatively small dia-meter. The choke at the forward end of the bag is marked "4". There is no igniter. This section is inserted into the propellant cylinder in Vorkart. 3 when used.

The bag of each section is stencilled in black to indicate the designation of the section and the equipment, the weight, nature and size of the propellant charge, the place and year of manufacture of the propellant and the place, lot, month and year of filling. Sec-tion suitable for use in hot climates are marked in red "Auch für Tropen" or "Für Tropen P.T. + 25° C".

Three types of case are known to be used. These are 28.5 inches in length and taper from 7.8 in front of the flange to 7.4 inches at the mouth. The first is a solid drawn brass case with the model number 6324 stamped in the base. The second type is a steel case of similar construction to the first. This case may be coated with brass or be rustproofed and has the letter "St" after the model num-ber.

The third type is a built-up case of steel and is of unusual design. The case consists of a coiled body which is attached to the base by a retaining plate and screwed collar assem-bled on the primer boss. The body is formed from a four-sided sheet of steel which is shaped and coiled so that there are three and a quarter turns at the base end and only about one and a quarter at the mouth. This is apparently intended to give the case greater strenght at the base. One edge of the coiled sheet forms an inclined overlapping joint extending along the length and partailly round the body. A layer of black wax is used between the overlapping coils presumably to assist in waterproofing. At the base end the coiled wall is turned inwards to form a curved internal flange corresponding to the upper side of the steel base. The body is made from low carbon rimming steel and has a V.D. hardness figure increasing, rather irregularly, from 105 near the base to 133 at the mouth.

The steel base has the usual external flange or rim and primer hole. The primer boss is screwthreaded externally to receive the screwed steel collar which bears on the steel retaining plate fittings around the boss and over-lapping the internal flange on the body. The retaining plate is circular with a central hole to fit over the primer boss and has two circular grooves near its circumference where it is curved upwards to correspond with the flange on the body. A cardboard disc with is surface covered with black wax inserted beneath the retaining plate to seal the joint. The stamping in the base of the case inclu-des the model number "6324/78 C" and the designation "17 cm K. Mrs.L.". Four equally spaced circular recesses are formed in the base for the purpose of assembly.

Fig. 17