I have read about loading round balls with two donut wads to center it.
One on the back and another at the front of the ball.
It is suposed to be the way RB are loaded in Russia.
Have anyone use it?

I ask because I’m working on an article for a gun magazine trying some options for shooting solid bullet from shotguns.
We can buy some brenneke and forster slugs here (Argentina) but the only RB we can get is the .575" muzzleloading.
I think this ball can work on 20ga cylinder and 16ga choked guns.
What about 12ga? It would be difficult to crimp into a 12ga hull except if I can put a donut wad on top.
Any thought would help.
Thanks
Martin