I tried it today with my cylander bore 20 ga. The first pic is my normal load. 60gr. 3Fg, over shot card, 1/4" fiber wad, 1 1/4 oz #6 shot and topped with full 1/2" fiber wad.
Pic #2 is the same load except with a shot cup on top od the 1/4" Wad. Both with and without the wad over the shot...