It has been a long time since I shot any Pyrodex. When I did it was my standard load for my ROAs and that is 30gr.
I shoot a lot of subs and the current one is Goex Pinnacle, made by APP for Goex. A 30 gr load is plenty accurate at 25 yards and less. Of course there is a BUT, and that is that the 30gr load, the 457 pure lead ball, the wad forced me to file the sights to get there. The ROA sights, and mine are fixed ones are too danged high. I always figured that was for 40gr loads. I don't know. They are too high. My windage was a tad off on all 4 ROAs I have. I made the adjustment by widening the rear slot to one side or another to make the adjustment. If they were off more I would have had to turn the barrel.
That is the fun of C&Bs, the tuning and experimenting with each one for the best results. Keep at it and try different loadings and powders too if you can.
ROAs are stout, the chambers are deep, but best of all is the Ruger bushing. That pin bushing keeps them running and the pin clean. The cylinders don't bind like in my other C&Bs near as easy.