I had a buddy that passed on, that shot a Beretta, but don't know what type of a choke he used, so I'm of little help.
Best is to post this on the shooting page
But you can start, by putting your full choke in, and shooting your preferred shell, at targets with turkey heads, at different yardages, to check your pellet density.
I'm sure someone had more better info. than me, on the tube choice