Couple of things...Yes you can have too much choke...and the pattern will start to "spray" when you do...Shot size can make a big difference...even in the same brand loads...I would also try the Federal 3 inch 2 oz loads...I have a buddy with a 835..thing didn't like 3 1/2s...I shoot a 3 inch so I tried a couple of my 2 oz #5s...helped tremendously...Still doesn't do as well as my Browning, but he is putting 10-12 in the kill zone at 40 yards...I would say to get consistent out to 45 plus yards and have the knock down you will need then you will have to get into the Heavy Shot type loads...My Browning B-80 puts 12-16 in the kill zone at 40 and 8-10 at 50....But I have never shot a turkey with a shotgun past 40 yards...Probably never will....