However, I'll have to try some in this Uberti-made Remington replica. Perhaps this revolver has some special ju-ju.
For the record, this same revolver with .454 inch balls, over 30 grs. of FFFG black powder, and a wool felt wad greased with Gatofeo No. 1 Bullet Lubricant will sometimes put all six balls into a 1" group.
http://thefiringline.com/forums/showthread.php?t=374009&highlight=uberti+1858