I have a question that I would like some help with. I have a Beretta al 391 teknys field that I have been using for sporting clays. I would like to get extended silver choke tubes for it, but I am somewhat confused. My gun has optima-plus flush tubes with the threads towards the middle. I assume that the optima extended chokes will not work due to the threads being near the top. So my ? is do I need the optima-plus chokes, and also in my beretta catalog they only make those in black is there someplace where I can get extended silver chokes in the optima-plus? Thanks in advance for any help given.