this is just a single shot 20ga no choke. ive killed grouse out to 50yds with it...but thats beyond any sort of "pattern" and more of a lob shot.
I used a 20 ga, full chokd barrel in an H&R single shot for a back up, my wife dropped a bird stone dead last year with that gun using plain old #4 federal( Not Turkey loads) As long as you can get a decent pattern and limit your distances, I won't go over 35 yards with mine.