Dano,
Welcome to Old Gobbler. I know that you will find a warehouse full of first hand knowledge about anything having to do with turkey hunting on the board.
As far as your question, if you will go over to the "Turkey Gun Pattern Pictures" section on the main board, you will probably find several posts from folks that have tried various shell and choke tube combinations through the same model gun as yours, complete with numbers and photos. There are presently almost 4000 posts in almost 400 different topics in that section. Take a few minutes and do a quick search through the topics and see if you can find what you are looking for, or at least get a head start on your own testing.
FullChoke