High explosive shell for Schneider 75mm field guns



The high explosive shell was composed by the body with its cap screwed on the head, the bursting charge, the copper driving band and the percussion fuze.


The shell body. It was made of steel, with thick base and thick walls. The inner chamber was cylindrical in shape and extended up to the base, in order to assure the centring of the bursting charge. It had a central cavity, where was screwed the primer box, which plugged the shell and where was screwed the fuze with the booster. The chamber was varnished up to the beginning of the grooves and contained a smoke-producing charge pressed into the shell, in order to leave enough room for the bursting charge.


The bursting charge. It was composed by 140 g of picric acid (Melinite) and a detonating primer (exploder). The picric acid (c) was contained in a cardboard casing, covered with a cover. The primer was composed by a booster of fine grain nitro-glycerine powder (a), contained in a steel cylinder, and an igniter of picric powder (b), contained in a tin box. On discharge, the flash from the fuze ignited the fine grain powder; the cylinder burst with great violence and partially detonated the primer, instead of merely igniting it. The primer in turn completely detonated the bursting charge.


The driving band. See the shrapnel.


The percussion fuze. It was composed by body (a), lead base plug (b), firing pin (c), safety spring (d), retracting girdle (e), spiral spring (f), primer (g) with detonating composition cup (h) and threatened cap (i).

The body had a hollow containing the firing and the safety devices. The base plug was intended to absorb as far as possible the blow transmitted by the firing pin, when the gun was fired. The safety spring and the retracting girdle prevented the fall of the firing pin before the shot. When the shell was fired, the spiral spring hindered the fall of the firing pin on the detonating composition cup, but when the shell hit the target, the firing pin and the retracting girdle, having already compressed the little safety spring, snap up by inertia and the needle penetrated into the cup, igniting the powder stored inside.







H.E. shell







T&P Fuze

H.E. Shell