After World War Two, the new NATO defense alliance held a series of trials to adopt a standard cartridge and infantry rifle. This would eventually devolve and the goal of a standardized rifle would be abandoned, but during the early trials there were three main contenders: the British EM-2, the American T-25, and the Belgian FAL. The Fusil Automatique Leger was designed by Dieudonne Saive and originally presented to the British government in 8mm Kurz, before being scaled up to accommodate the British request to use the .280 cartridge. A small number of these prototype FAL rifles in .280 were delivered by FN, and used in the 1950 NATO rifle trials.
Many thanks to the Royal Armouries for allowing me to film and disassemble this very scarce trials rifle! The NFC collection there – perhaps the best military small arms collection in Western Europe – is available by appointment to researchers, and you can browse the various Armouries collections online.