No. I don't know where you heard that, but the Exocet is just average as an anti-shipping missile. The only reason it's famous is that it ruined a few British ships in the Falklands. (which was due more to bad construction and tactics than it being a spectacular missile)Riddle78 said:is reputed to have a 1:1 fired:sink ratio.
Anyway, on topic, you can build just about any action with any caliber, but there are three problems with that idea. First, a shotgun is a close-range weapon best suited to close quarters and entry, whereas a minigun is a gigantic point-defense or suppression weapon - the concepts don't mix well. Second, the continuous average recoil from an M134 7.62 minigun exceeds 150 pounds. Now imagine trying to control several times that size round with a hand-operated weapon. Third, if you want really freaking big miniguns, try the aforementioned GAU-8/A from the A-10. 30mm six-barrel, 3900 RPM, fires a 1/4 mix of high explosive incendiary and DU armor piercing, and while it won't drop the aircraft out of the sky as stated, the peak recoil force IS about five tons - slightly more than half of the A-10's maximum thrust.