I could not do a five inch group at 50 yards but off a bench rest this day, I could hit in the red.. only three of the six mind you. And I forget the order of the shots. But these revolvers can do some impressive shooting.
This was much closer. 25 yard shooting off a bench rest I believe. And according to the notes on the photo I was testing cornmeal wads, VS no cornmeal wads.
Due to the size of that red bull, and the fliers.. I would guess those groups at about 3-4 inches off a bench rest. Plenty good for shooting a deer. But further then that I would not consider it.
That 38 grains of Triple Seven in your old army must have had quite the bark to it. I remember shooting 3f Triple Seven out of my Pietta and using the 30 grain flask. It did not take me too many shots to pull out my powder measure for a hand gun and start reducing the load. Not that I could not handle it.. I was worried more about the firearm. No use in stressing them.