Been a while, but I did have an M-2, which is basically the same barrel as the Vinci...
Mine shot the factory Full quite nicely out to (and past) 40 yards with Hevi-shot #6s...
I shot a variety of shot sizes and chokes with lead, and the Fiocchi Golden pheasant #6's probably patterned the best out of whatever turkey choke I was then shooting.... The Benelli did NOT seem to like larger shot sizes (than #6's) with the turkey choke (I believe Benelli has a smaller bore diameter if I recall correctly).