Well, we really don't keep tabs of records in airsoft (which should be a nice idea btw) so this one cannot be really confirmed. However, if nobody shows up with an old or newer video showing that theirs is the fastest, we can take this in good faith. Giaco Whatever shows how he is building his "World's Fastest Airsoft Gun" in this video... "I didn't actually calculated its speed yet but I'm pretty sure I'll make it the World's fastest airsoft gun... You'll see... ;)

Anyway, this will ultimately become an airsoft radio controlled turret machine gun but in this video I focused on making just the machine gun itself.

I only tested it with 130 PSI, the result is pretty great but not even near to its full capacity."