It doesnt mean bang, bang..remeber when mutu scored the goal in the game where he wanted to cross it and it went into the goal from the left side of the 18 and he turned around but did the same expression to Cappello meaning "che culo" meaning what look but, there are two different meanings one meaning what luck and other simple meaning "Te faccio una mazzata" really means i will make ur face swollen..but it one of those things you can't translate word for word in english. Vincenzo was simply saying he was going to bring him pain or make him feel pain..Iam loving it