The case of the fixed Q.F. ammunition is of solid drawn steel, electroplated with brass. A screwthreaded primer hole is formed in the base, the body taper increases sharply near the neck and the overall length is 41.8 cm.

The propellant charge consists of a viscose rayon bag containing graphited flake propel-lant and a 30 cm tube of propellant nearly half of which protrudes above the chocked mouth of the bag. The external and internal diameter of the tube are 0.665 – 0.5 cm. An annular bag, containing 5 grams of potassium sulphate, is attached round the choked mouth of the bag and the tube. This is presumably intended to reduce the flash. The flake intended to be flashes and contains diethylene diglycoldinitrate, nitroguanidine and nitrocellulose; no stabilizer is added. The dimensions of the flakes are 4 x 4 x 6 mm and the mean weight per flake is 0.154 gram. The tubular core is a cordite type propellant containing nitrocellulose and diethylene diglycol dinitrate with akardite.

The igniter composition consisting of small graphited cylinders of nitrocellulose powder without surface moderant is contained in a  viscose rayon bag stitched to the under side of the bag containing the charge.e bottom of the bag is of cotton dyed pink.

The percussion primer is of the normal German type and consists of a brass body with the enclosed cap and brass anvil plug. The cap filling is shaped to fit round the anvil and consists of mercury fulminate 28 per cent, potassium chlorate 34 per cent, antimony sulphide 32 per cent, and glass powder 6 per cent. The cap is a push fit in the underside of the anvil plug. The magazine contains a 1.44 grams pellet of gunpowder over 0.65 gram of granular gunpowder. The primer is closed by a brass washer and varnished fabric disc.

Fig. 4 – German Percussion Primer 5 cm Q.F. Cartridge

The filling, in a paper container which is cemented to the wall of the shell, consists main-ly of pressed T.N.T. over which a smoke box is positioned in a surround of cast T.N.T. The exploder system consists of 7.6 gram pellet of P.E.T.N./Wax (90/10) over a 9.2 gram pellet of P.E.T.N./Wax (91/9). The total weight of the filling is 5 oz. 14 dr. and the complete weight of the shell 3 lb. 5 oz.

The smoke box, which weighs 10.6 grams, is similar to that the 7.5 cm H.E. shell but is smaller.

Fig. 5 – German 5 cm H.E. Shell

The fuze used is the A.Z. 39 which is a detonating type with a direct action in which the needle is supported by a shutter.

The direct action mechanism consists of an aluminium needle supported over the detona-tor by the shutter, which engages under the enlarged head on the needle. An aluminium striker is positioned in front of the needle in a recess in the cap of the fuze. The recess is closed against air pressure by an aluminium disc.

The shutter slides in a diametrical groove in the front face of the body where it is retai-ned in the safe position by means of two centrifugal bolts. The bolts are housed in holes in the body within an expanding spring ring and engage in slots in the shutter. The shut-ter has two holes formed in it, one each side of its centre. One of these holes has for-med in the inner side of its periphery a recess which extends in the centre of the shutter and receives the needle. The dimensions of the recess prevents the head of the needle passing it but the hole will permit this movement when the shutter is in the armed posi-tion. With the shutter in the un-armed position the second hole coincides with a channel in the body which houses a steel ball.

The brass magazine of the fuze is fitted to the underside of the body by means of an aluminium screwed plug. The magazine is fitted with a brass detonator containing 0.33 grams of lead azide with calcium silicide over a filling of 0.48 grams P.E.T.N.

On acceleration the ball is held in the channel by set back. During flight the ball is cau-sed to move forward by creep action combined with the effect of the slope of the chan-nel and centrifugal force until it enters the hole in the shutter. The rotation of the shell also causes the spring ring to expand and the bolts and the bolts to disengage the shut-ter which, with the ball as a displaced weight, slides across the body and ceases to sup-port the needle at the head. The needle is then held off the detonator by creep action. On impact the needle is driven in and pierces the detonator.

Fig. 6