British No 4 Mk1 No. 68 Anti-Tank Rifle Grenade, 1942 AFAIK 51mm cumulative grenades No.68 model1940 were used with a 51mm rifle grenade launcher. The shot was performed by a rifle dry shot from the lying support only. It is fired from the No. 1 Mk 1 rifle-bomb discharger cup that fits on the end of the rifle. The grenade is launched using a blank cartridge and was first in use in late WW 1. The Gunner had to take out the axle-pin and screw stabilizer before firing. Such grenades were used in France in 1940 and also by the Home Guard in 1941 - 1942. A 51mm standard army mortar could fire such grenades. These grenades were manufactured by the A and F Pears and the Peterborough Die Casting Company, H 6.5in x 2.5in diameter. Physical description main body, cap, fin, inner tube, inner cup cast metal cup main body, open and threaded top with threaded hole in base; solid flat cap screwed on to top; four fins (with lateral gas check plate screwed on to bottom) screwed in to grenade base; split pin inserted through fin shaft with warning plate; rubber inner tube inserted into main body; cast flat cup on top of inner under cap; painted yellow. Length - 6.5in x 2.5in diameter. [1] embossed (on fins) [2] embossed (on main body) [3] printed (on plate attached to safety pin) [1] No68 ATI/L 1942 PDC A & F P [2] P D C [3] TO BE WITHDRAWN FROM GRENADE BEFORE FIRING