I recently purchased a Benelli M2 with a 21" barrel, I haven't gotten a choke yet but I have a Super Black Eagle 2 with several chokes that fir. Rhino, Jelly Head, Hevi 13, and a few others. I have been shooting Nitro shells and the Magnum blends. But all of them are 3.5" and this is a 3" gun. I want to shoot the Federal Heavyweight #7 3" that I have but you need a choke that is not ported, any suggestions? I was told to try Rob Roberts .650 or .655 chokes, does anyone have any feedback? Thanks