The fixed Q.F. round is fired from the 47 mm 32 calibre anti-tank gun, model 35.

The weight of the complete round is approximately 6 lb. 4 oz. and the overall length 14.1 inches. The shell is coloured pale blue with a  red head and a green band immediately in front of the driving band. The T.N.T. bursting charge is indicated by the stencilling "TRI-TOLO".

H.E. shell filled T.N.T.

Combined graze and direct action fuze with gaine.

Brass cartridge case.

Propellant charge of double base composition.

Percussion primer, model 35.

The shell, without the fuze, is approximately 9.2 inches in length, and weighs 5.2 lb. filled and fuzed. The ratio of length to diameter is abnormally high, and the copper driving band is more than a third of the length from the base. The shell is machined from rolled bar steel and has a parallel walled cavity of the same diameter as the fuze hole, and is thus suitable for block filling. The exterior of the shell is thinly coated with zinc before colouring. There is no base plate.

The bursting charge consists of five pressed pellets of T.N.T. in a transparent paper wrapper. The uppermost pellet has a cavity to receive the gaine fitted to the fuze. A felt disc is inserted in the base of the shell cavity below the filling and a washer of the same material is inserted between the top of the filling and the fuze. The weight of the burst-ing charge is 5 oz. 3 1/2 dr.

The fuze has a combined graze and direct action, and is fitted with a 0.89 gram cyclo-nite gaine to obtain detonation.

The body of the fuze is screw-threaded externally for insertion in the shell and is prepa-red at the base to receive the gaine container. The threaded portion os of 1.14 inch dia-meter and the pitch approximately 2 mm. At the front end a screw-threaded recess is formed to receive the needle pellet holder, which also provides the means of attachment for the screwed head of the fuze. A large recess in the centre of the body accommoda-tes the graze pellet and has a flash channel at the base leading to the magazine. A late-ral channel containing a masking bolt inter-sects the flash channel and is closed at both ends by aluminium discs. These discs are covered by an aluminium sleeve which is fitted round the body below the screw-threads. Another lateral channel is formed in the upper part of the body to accommodate the centrifugal locking bolt which passes through holes in the graze pellet and the needle pellet. The bolt is retained in position (so that its pro-ducing ends engage in the channel on each side of the graze pellet) by two spring-loa-ded detents. The detents and springs are carried in recesses formed in the body. The la-teral channel is intersected by these recesses and is closed at the ends by screwed plugs. An inclined channel, between the screw-threaded portion of the body and the re-cess for the graze pellet, contains a centrifugal bolt, which is stepped to engage the base of the graze pellet.

The needle pellet is fitted with a shearing wire near its front end. The protruding ends of the wire impede the passage of the pellet through the hole in the holder. A second wire with protruding ends is fitted in the needle pellet to engage the mouth of the cup-sha-ped graze pellet and thus prevent creep during deceleration in flight. A channel is formed in the needle pellet to coincide with the holes in the wall of the graze pellet and to recei-ve the centrifugal locking bolt.

The graze pellet is in the form of a cup, the mouth of which fits over the lower end of the needle pellet. An igniferous detonator is fitted inside the base of the cup, and below this a flash channel passes through a spigot formed on the base. The spigot engages in a recess in the masking bolt and locks it in the masking position. The detonator consists of an inner and outer copper cylinder with a tinfoil lining and a copper closing disc at each end, and contains a 0.8 grain filling consisting of mercury fulminate 6.6 per cent, potas-sium chlorate 40.5 per cent, anti-mony sulphide 47.8 per cent, and grit 5.1 per cent.

The masking bolt consists of a hollow cylinder with a recess to engage the spigot at the base of the graze pellet.

The 0.89 gram cyclonite gaine fitted to the fuze is described in the section on Italian gaines in this pamphlet. In this instance the outer cup does not contain a powder pellet.

On acceleration the two detents set back, leaving the upper lateral channel clear for subsequent movement of the centrifugal locking bolt. The detents are held back during flight by the friction resulting from spin.

During the period of deceleration in flight the locking bolt and lifting bolt are thrown out-wards by centrifugal force, and the graze pellet, assisted by the lifting movement impar-ted by the step on the lower centrifugal bolt, creeps forward to the limit imposed by the creep wire and thus disengages the recess in the masking bolt. The masking bolt is then thrown clear of the flash-hole leading to the gaine. Further creep of the graze pellet du-ring deceleration in flight is prevented by the creep wire.

On graze, the graze pellet, by its momentum, overcomes the creep wire and moves for-ward over the needle pellet, carrying the detonator on to the needle. Dependent on the resistance offered by the surface struck and the angle of the strike, the needle pellet may be driven in, severing its shearing wire, and piercing the detonator as the graze pel-let moves forward. The flash from the detonator passes through the flash channel to the mixture of lead styphnate and lead azide in the head of the gaine, which brings about the detonation of the cyclonite filling.

The brass case is 7.7 inches long and is not necked. The shell is a close fit in the mouth of the case, and is not secured by coning or indenting.

The charge consists of approximately 6 oz. 8 dr. of double base flake propellant in four 46 gram bags. The dimensions of the graphited flakes are 0.1182 x 0.138 inches and the composition, nitrocellulose 62.36 per cent (nitrogen content 12.41 per cent), nitrogly-cerine 33.9 per cent, centralite 1.98 per cent, mineral jelly 0.95 per cent, and graphite 0.81 per cent.

The percussion primer used, model 35, is described in this pamphlet.