I make sure my revolvers have well cut forcing cones, use the shortest case I can use, (45 CS, 44 Russian) a full case of good 3f powder (Olde Eynesford or Swiss) and a bullet of this general design.
http://www.accuratemolds.com/bullet_detail.php?bullet=43-215CMy lube is a mix of Beeswax and Olive oil.
I would make sure the cylinder has a proper black powder bevel on the front edge. (New production has none!) I have swapped off or bought/sold my top breaks until all are now Navy Arms imports, which have the best bevel of all the importers observed. (IMHO) That does make them all 2006 or earlier. This is a 5" Schofield, a 7" Schofield, and a 3rd Model Russian.
In addition, the early 3rd Model Russians have a gas collar twice as long as all other Uberti top breaks, comes only in 44 Russian, and is the best performing of my Top Breaks with BP, though the 7" Schofield is almost as good.
The 5" likes 777 best. I have found 777 to be a good performing powder in all my top breaks, increasing reliability in a more marginal gun, like the 5" Schofield. I prefer real black for its milder corrosion properties, but the revolver tells me what it likes best. Plenty of water is key with 777.
All 3 of these revolvers will shoot a complete match without cleaning with these components.