I played around with 1/2" "cushion" wads, in combinations with OS Cards. I was not happy with the patterns.
The heavy .5" fiber wads tend to follow the shot, and bump it after it leaves the barrel, causing " Donut Hole" patterns. You will be better off using smaller wads( 1/8") stacked, to make that 3/8" or 1/2" Wad you want to try behind your shot. Then as they leave the muzzle, they separate. Putting a hole with an awl through the wads, off-center, so that holes do not line up with the one next to it also helps them separate and fall out of the line of fire. The sooner they fall away, the better the patterns.
I have tried using, 2 OS CARDS( .10"), 3 OS cards, and 4 OS cards under a powder charge, and those thinner cards work fine.
Iron Jim Rockham came up with this " system" here, a couple of years ago, to use in his new, 20 gauge fowler, so that he only had to carry ONE "wad" in his pockets or bag when he was hunting. He put 4 cards under the shot, with a ball of waxy lube between the 3rd and 4th cards, then the load of shot, followed by 2 OS cards, to lock the cards and shot load in place and keep the shot from moving during a hunt. The benefit of using cards is that they are thin enough to BEND when fitting them down a CHOKED barrel, and then turn them when they have passed the choke.
I didn't have the waxy lube he could ball up, so instead, I used a greasy cleaning patch( Wonderlube) to run down the bore in front of the jag, as I was seating the OS cards on my shot load. The cleaning patch came out of the gun with my jag, and left the barrel from the OS cards to the muzzle greased. That prevents rust, softens the powder residue, and also greases the barrel so that the shot pellets, on the outer sides of the shot load, slide over the bore better, rather than rub lead off and get "flats" on the pellets. I found I got more pellets in my patterns out at 25 yds, lubing the barrel this way. When I cleaned my gun, I didn't find lead streaks in the bore, as I experienced without greasing the barrel. :surrender: :thumbsup: