fadetoblack188,
I have the black diamond, but on my Mossberg 835 which is a 24" barrel. I know it's pricey, but give the Hevi-Shot magnum blend a try. Started using this choke/shell combo last year and both birds were single shot...and drop! I shoot the 3" 2oz. Patterned about six inches high @ 40 yards compared to the factory choke just FYI. Good luck and let us know how she does!
Brandon K