"You could do it with a Colt, but that was a bit more complicated. Go to half cock, pull the barrel wedge out, pull the barrel assembly off, pull the cylinder, put the fresh one in, put the barrel assembly back, and insert the barrel wedge. The problem was keeping track of the wedge, I suspect that it went into the mouth, the barrel assembly got tucked into the belt or shir, or mabye the inner jacet pocket."

I'm not sure about replicas, but original Colt 1860 Army wedges had a slot along the top of the wedge, with a lip at the end to capture the wedge against the screw holding it in. This was the case wth the original I used to own. (It was stolen.) When the wedge was knocked out of the barrel, the lip stopped it from falling out. To remove it, you had to remove the screw holding it in place. The screw did not keep the wedge tight; friction did that. Even so, changing cylinders, or loading the pistol on horseback would have been very difficult, especially in the heat of battle. You could still drop the whole barrel/rammer assembly, or one of the cylinders. Every mention I have seen, and a lot of pictures, Mosby coming to mind, showed multiple pistols being carried, for a "New York reload". Stan