I am looking for a turkey choke for a 28 ga. If I do a % of the 12 and 20 ga chokes I use, I get .919 or 91.9% of the original bore. Does this mean that the same % will work in a 28? I know, ask William at Sumtoy, I am just looking for input. I will contact the manufacturer if need be. I had Briley thread my old SKB 20 model 7300 and the built me a choke on the specs I gave them. I used a friends production choke that came with his gun and I love the choke. I am wondering if they are the best option. I don't need it threaded, but will probably need a custom choke. Any thoughts or info is welcome. Thanks, Al Baker