From what I have heard, the 7.62 conversions were not very successful. All were done in house by Century. The original barrel was set back and reamed, and that put the gas vent closer to the chamber. The result is hard extraction because the case is still slightly pressurized. Some work fine, some don't. Various fixes are recommended, like polishing the hell out of the chamber, downloading or using the Hornady TAP ammo with the black case.
That said, I would LOVE to have one in either calibre, but as mentioned, very few up here.
I don't beleive that the French made a factory 7.62 version, though they did offer FR sniper rifles and AA-52 GPMGs in 7.62 NATO.