I used to shoot cowboy with an FBI agent who always used 40 grains FFFg in his ROAs.
His theory was, that since he shot guns "for a living", he didn't want to get used to light loads.
He always hit the pistol targets, but I have no idea about his groups.
If that's not enough powder for you, ClassicBallistx makes a cylinder that holds 5 grains more.
If you shoot 'em a lot (In cowboy Action, we shoot 6 or more 5-shot stages at a match), and you shoot real black powder, since there is no shielding of the base pin from powder residue in the front of the cylinder, Remmies bind up after a few shots.
Mine could not get through a 5-shot stage without significant binding.
Remmies also have a reputation of breaking hand springs.
I can't shoot them comfortably, as the back of the triggerguard beats up the knuckle on the middle finger of my gun hand.
The hammer has a large arc, so by the end of the day, it puts a lot of wear on my cocking thumb.
ROAs don't have any of these issues.
Don't get me wrong, I like Remmies, but the design of the Ruger is better thought out, and it is a much better gun.
Yes, they are pricey, but you will pass it down to your son, who will pass it down to his, etc.
--Dawg