I have been shooting the 1860 Ubertis about a year and the only
modification was the Thunder Ridge nipples, other than that they are factory,they have nice smooth actions, and nothing has broken.
I have been using Elephant FFG, enough to fill the cylinders,
and they just keep on going, nice boom and on target.
Seems like the trick is keeping the lube over the balls and the things will shoot all day.
I have used 3f, and with the cylinders full it makes one hell of a boom, but...I have a cache of ffg so that is my powder of choice. ( might try some of the Goex Cowboy I got fer free)
I figured Col. Colt made those cylinders to be filled up!