That full cushion wad is still too much. It bumping your shot after it leaves the barrel. Cut that cushion wad in half or in thirds, or eliminate its use all together. Its not needed. Just grease up a cleaning patch and run it down the barrel after seating the over shot cards. The grease protects the bore from rust, during your hunt, it slicks the walls of the bore so that lead does not scrape off it, harming subsequent patterns because of the constantly building but changing lengths and layers of streaks of lead in the bore, and it will soften the residue of the powder for easier cleaning.
If you want to use paper to make shotcups, you have to use fairly thick paper, like that used in coin wrappers, or index cards stock. Use the next gauge smaller wad on the inside of the cup to help form the base, which is folded over the end, and in my case, dipped in melted parafin wax, then struck on wax paper on my counter top to cool and harden with the end closed tight.
I cut slits in the mouth of the cups to create " petals" similar to what you see in modern plastic cups. This acts as an air brake, and allows the wad to separate from the shot quickly on leaving the barrel. Without the slits, you are sending a shotgun slug, made of paper covered shot, down range.
This is the same problem you get from using the full cushion wads in a load without paper cups. If you think in terms of NASCAR racing, those boys call it " drafting ", where the car behind is actually able to gain speed on the front car, by staying in its draft or " vacuum", and then slingshotting itself past the front car on the inside of a turn, when the vacuum is going to swing outside the turn's edge, anyway.
Its actually a law of physics, that explains gravity, in that all large or heavy objects tend to pull lighter objects to them. The lead shot, on leaving the muzzle, is heavier, of course, than the cushion wad, even when the wad is wet with lube. The wad is therefore pulled into the back of the shot column, where it bumps it. The bump has the same effect as a cue ball does hitting a rack of balls on the pool table: the balls go everywhere, but straight ahead. As the shot spreads, air enters this vacuum, and the vacuum vanishes, typically in 9 feet, or so. But the damage is already done. Jim Rackham's advice on using only OS cards to build a shotgun load is good advice because iT RECOGNIZES that the Laws of Physics are not suspended for BP shotguns. By putting holes in each of the OS cards, air is able to separate cards from each other almost as soon as they leave the muzzle, so that they DON"T follow and bump the shot column by being sucked into the back of the shot, and hanging in the draft, or vacuum created by the shot when it exits the barrel.
