Littlejohn adaptor

The Littlejohn adaptor was a device that could be added to the British QF 2 pounder (40 mm) anti-tank gun. It was used to extend the service life of the 2-pounder during the Second World War by converting it to squeeze bore operation. "Littlejohn" came from the calque, i.e. literal anglicization, of the name of František Janeček, the Czech designer and factory owner who had been working on the squeeze-bore principle in the 1930s and his son František Karel Janeček, who had brought his know-how to Britain after fleeing from German-occupied Czechoslovakia.

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