It amazes me the variance you get from one load to the next. Even the same brand! I purchased an Indian Creek choke and patterned the Winchester X-tended, and the Hevi-13 in 1 5/8oz, 1 3/4oz, and 2 oz. The variance in the Hevi-13 loads alone was huge. I ended up getting wicked patterns with the old white shelled Hevi-13 whihc you can't get anymore. Winchester X-tended was a clear second. I have also seen significant variance from 2 of the same brandgun and choke shooting shells from the same box!

The point I guess is it really can't be answered by anyone except the gun. You need to start with a good quality turkey choke. A gun like you have, has been made with a turkey choke already but if you really want to tweak it you gonna have to try others. If you're trying to stay in a budget swapshells with a buddy. You buy a box of one kind and find some friends who buy others. Everyone swap a few shells of each.

I would always recommend going with a number 6, expecially if you're shooting a heavy synthetic load like Winchester x-tended or Hevi-13 or the Rem Wingmaster HD. More pellet count is your friend and all those loads will give you knockdown at 40 yds shooting a 12 guage no problem (this edition of "Turkey Call" has a article on this discussion)

That gun definitley has a load whihc will give you a great pattern to 40 yds. Just have to find it.