I'm listening!
There is further load development work to do with that WR too (also the Purdey, and some cartridge-case experiments I want to do with the Mahillon).
On Black Powder cleanup, I'm definitely with you on that point.
There's a lot of surface area on a SxS bore-rifle, why complicate matters with caustic solvents!!?

RigbyMauser-

Have you checked for movement of the bullet in the second barrel cartridge after firing the first?
Just curious -- those point-crimps are Victorian-Cool!

We need a U-Tube update of your shooting exploits with that 10-bore.
Get cracking!

Cheers
Tinker