(Fig. 18)

The cartridge is used in the 10.5 cm recoilless airborne gun (10.5 L.G. 40, previously known as l.G. 2) and is a separate loading type with a plastic disc closing the base and a percussion primer fitted in the side of the case near the base.

The designation of the equipment is given on the label attached to the closing cup in the mouth of the case and is also imprinted in a circle on the plastic base. Only the earlier designation "l.G. 2" or "L.G. 2" has been found on cartridges examined to date.

The steel case, plated with brass, is 15.7 inches in lenght and tapers from 4.9 inches in front of the flange to 4.73 inches at the mouth. A larger circular hole in the base has an internal flange on which a disc of brown plastic inside the base of the case is supported. A locating plate for the primer is fitted to the wall of the case near the base. The plate has a projection at the base which engages in a recess in the flange of the case and, near its forward end, is bored and screwthreaded to receive a screwed adapter for the primer. The inner end of the adapter engages a curved rectangular plate inside the case. This plate has a central hole for the adapter and, at its base, has a projection which en-gages a step formed in the plastic base piece.

The base piece is 4.1 inches in diameter and 1.1 inches in depth. The forward end of the cylindrical disc of plastic is chamfered along the part of its circumference which corres-ponds with the primer. The base is inserted with an adhesive and is located by a step at one end of the chamfer engaging the projection at the base end of the inner plate. Coin-ciding lines on the base of the plastic disc and under the flange of the case indicate the correct position for assembly.

The following variations in the construction of the case have been met with:–

The charge is contained in a cylindrical bag of white artifical silk with an igniter at the base which also extends to form a collar around the lower end of the bag. The mouth of the bag may be choked or folded flat and secured by adhesive.

The 6-lb. 11-oz. 4 1/4-dr. propellant charge consists of a double base propellant (nitro-cellulose and diethylene glycoldinitrate, including nitroguanidine) in the form of tubular cords, the diameter of the tubes being 0.102 inch externally and 0.039 inch internally. The charge is arranges in two bundles on above the other. The bundle at the base con-sists of 2.4 inch tubular cords contained in a paper cylinder which has an external flange at the top. The tubular cords in the upper bundle are 11 inches in length and are secured by ties. The weights of the lower and upper bundles are 14 oz. and 5 lb. 13 oz. 4 1/4 dr. respectively. The markings indicating the weight, nature and size of the propellant are shown in the drawing.

The igniter, in the form of a cap which fits over the base of the cartridge bag, contains 30 grams (approximately 1 oz. 1 dr.) of the nitrocellulose powder Nz. Man.N.P. (1,5 x 1,5). This is the powder normally used for igniters and consists of nitrocellulose with the addition of potassium nitrate and is in the form of cylindrical grains. The white material forming the igniter bag is stitched to form nine compartments for the powder at the base and twelve compartments in the band which fits around the lower end of the cartridge bag.

The charge is retained in the case by a cardboard cup inserted in the mouth of the case. The cup carries and adhesive label giving the same patriculars as those marked on the bag.

The cartridge is carried in a rolled paper container weighing 2 lb. 10 1/2 oz. The approxi-mate overall dimensions of the container are, length 16 inches, diameter 5.8 inches.

Fig. 18