I bought the mesh sizes I needed in steel screen by the square foot from McMaster-Carr in Jersey, built a simple wood frame for them and sift the shot through them.
They have a steel mesh of .035" wire with .09" openings (#9 shot is .08" diameter) that should work for you for $5.75/ft².
Keller
They have a steel mesh of .035" wire with .09" openings (#9 shot is .08" diameter) that should work for you for $5.75/ft².
Keller