Alright I'm trying to get some actual tested facts. I've got a Mossberg 500 12ga 28" barrel, what I need to know is what choke and shell combination seems to work best, I'm leaning towards the Carlsons choke .670, shooting hevi 13 mag blends. If any one had this particular setup let me know what kinda numbers you get.
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
Welcome to OG. We're glad you're here. This is an excellent site and there are many helpful hunters and shooters here who will do all they can to be of assistance to you.
I have a variety of Mossberg shotguns including one like you describe. There are many chokes that will work well for you. Each choke maker uses a design that he feels is best in his particular choke tube. Some are pretty simple and straight forward, others are more complex but most work well.
I much prefer the standard load of Hevi-13 to the Magnum Blend shells but many others prefer the Magnum Blends. Both loads work well and will kill a turkey at any reasonable range.
I would recommend that you take a few minutes and "deep clean" the barrel of your gun. That process is very inexpensive, takes a little time but will pay dividends to you no matter which turkey choke you choose.
My only comment about chokes would be that in my experience a choke with an exit diameter of .670, especially one with a pretty short parallel section, might be just a little too open for your standard bore Mossberg shotgun and those shells.
Thanks,
Clark