A little late to the party......
I have two Uberti-made, Taylor's in 1871-72 Open Tops (which are quite similar but with some differences) in the same caliber (with 4 3/4" barrels) I shoot in SASS matches. I shoot 38 special in them. I agree with a prior post that suggests to stay away from the "hot" or +P loads. I shoot "cowboy loads" of 125 gn or 158 gn at 700-800 fps without issue. Accuracy is very good. I cut the center out of a playing card at 7 yards in a side match last month.