I to shoot a TK2000, 209 primer, with the new compensated choke. This choke really reduces the felt recoil of the 2000. I tryed 7 1/2 shot mixed with 5 shot several times a couple of years ago. I was not real happy with the way it patterned. I have since gone back to #5 shot with 120 grains of Triple 7. I shot it a dozen times this past weekend, very tight patterns from 20-35 yards. Starts spreading out some at 40 yards, but I did have a number of the shot in the brain and neck bones on a turkey head and neck target at 40 yards. I would really like to try some Hevi-Shot in my TK2000, I have read several really good reports on it as far as tight patterns go out past the 35-45 yard mark. Good luck with your experiment, and please let me know how it turns out.