ed's article references Blue Dot as a suitable powder.

That's a curious choice for an antique revolver.

Were it mine, and I wanted to shoot it....

I would disassemble the factory rounds with an inertia bullet puller, fire the primers and reload the cases with Trail Boss and lead bullets.

This is assuming the cases are Boxer primed, and I have no clue if they are.

"The price of good shotgunnery is constant practice" - Fred Kimble