I wonder how both systems would deal with something like this:
http://www.youtube.com/watch?v=bD7xzMpLGWs
127mm Vulcano is not for AA/anti missile, 76mm Strales obviously are but at O.T.O Melara they are developing also an antiship/coastal support round for same mount: it would be perfect against somali pirates.
It is about forty years however that MMI uses excusively proximity fuses rounds for antimissile defence: 76mm compatto, 40/70 Dardo and Fast Forty , 76mm super Rapido and now 76mm guided Strales rounds.
the 76mm is going to be a full multi purpose gun, anti-missile, anti-aircraft, coastal fire support with GPS guided and extended range ammunitions and it can switch ammunition type in a few seconds