Many people on this site have done the work for you. Many choke manufacturers, shot shell manufacturers and others have done a lot of research with each gun and shell and can put you ON TARGET without breaking your bank. Since you know the gun you'll shoot and probably the shell and shot size, pay attention to what others have put in their guns and you won't have to Break the Bank. I setup an 835, 10 years ago, and decided on shooting Hevi 7's. Most of the 835 shooters on here suggested Pure Gold .670, Indian Creek .675 and Stardot .676 at the time so I bought the Pure Gold and never looked back. An even 300 plus at 40 was the result. IMO don't chase the numbers, find a choke that has an even pattern at the yardage you shoot most often, stick with it and have fun hunting. Chasing numbers and chokes can get REALLY pricey.