Hi,
Im back.
Those are the bullets I will try:
Form left to right:
20Ga slug (with double wad, 16Ga into 12Ga.); local made Brenneke; Winchester slug; italian slug (Dangerous game slug); .715 lead ball and .715 steel ball.

A friend offer this wad that looks good. I post a picture of the wad cutted to see it can work.

Im still waiting for the permision to use the gun.
I found that it will be harder to fix the scope as the band is not paralell to the barrels.
I have to file it at angle. More time and work.

Thansk
Martin