'Vulcan' is the name of the home planet of Mr. Spock from 'Star Trek.' If you're a Trekkie, you might recall that the Vulcans came to the human race in peace. M61 Vulcans do not such thing.
They're an integral part of all 3,700 planes currently in the service of the US Navy, and their rate of fire is frightening. M61 Vulcans are effectively rotary Gatlin guns which can fire off 100 rounds every second. That's a powerful barrage.