Yes indeedling, even the Wikipedia entry on the FN FAL acknowledges this. There was also a version in .280 British, intended to compete with the EM-2. Manny Shinwell, then Minister of Defence, had the EM-2 adopted for service as the No. 9 rifle (see wonderful newsreel clip here http://www.britishpathe.com/video/new-rifle-test-for-experts which also has a glimpse of the TADEN MG) but unfortunately when Winnie returned to power he binned the EM-2 in order to comply with American insistence on the adoption of their over-powered .30 Light Rifle cartidge (developed from .300 Savage) as the new NATO standard.
In similar style, the M1 Garand was originally designed around the .276 Pedersen, a cartridge thought to be an ideal compromise of power and lightness from the results of the “Pig Board” trials. Only later was it redesigned to take .30-06.
It is fortunate indeed that both the Garand and the FN FAL worked satisfactorily with cartridges a good deal oofier that those they had been designed for.
All the best,