well for one IME the primos jellyhead is a better choke than the tightwad. that would be a good starting point. before TSS it was always a popular 870 choke. I used a .660 one back in the day with a 28" barrel. When i cut my barrel down to 21" i had sumtoy make me a choke for longbeard 6s. my barrel liked a .655 for those. It patterned excellent. he makes excellent chokes, and william spent a lot of time with long beard shells back when they were the thing. I would highly suggest contacting him, theres all kinds of stuff he can do or help you with including shipping your barrel and some shells to him for him to work with,