Ron, I would upgrade to a 12ga with screw in chokes, problem solved...#4 buck shot available in most places.
In the 20ga, #3 buck in 3" mags used to be available in 20ga for deer, you would have to pattern this buck shot to see if your shot gun would pattern at all....full choke is best for buckshot on yotes....probably not what you are quail hunting with.
