OK
the original Vulcan was a 6-barreled 20mm rotary weapon mounted on (at first) F-4s, later on F-14s and F-15s, F-16s
the handheld minigun in Predator was never actually issued for service, it's a rotary weapon in 5.56mm (same as the M-16)
i think you were referring to the GAU-8 Avenger which is the 30mm rotary canon mounted on the A-10
Anybody here ever heard footage of tank guns firing? JESUS CHRIST!