During that period of the Old West there was a rapid development in firearm technology and brass self-contained cartridges were just coming out. Modern firearms could be a little hard-to-obtain out there so it was common for a smith to modify a Civil War Cap & Ball pistol to one that used the newer technology.
Think of Clint Eastwood’s revolvers in “The Outlaw Josey Wales”. That was a converted Cap & Ball piece, but considering he was a Confederate soldier on the run immediately after the cessation of hostilities the weapon probably wouldn’t have been converted. Yet I don’t recall Clint ever shown reloading in that movie. Maybe he had a “Dirty Harry” speed-loader cobbled together considering the volume of lead he was putting out?
Its nice to learn new things. Your reply had me doing a little research. I actually have a Colt 1851 Navy Navy percussion in a display case (a very nice replica, not original) that was an award from Colt to me for my senior year engineering robotics project at USNA back in the early 1980’s. It has never been fired, just kept clean and displayed in its wood and glass case.
I was not aware there were conversion kits for it to allow it to fire a standard cartridge. I had seen Clint Eastwood carry and use this in ‘The Good, Bad, and Ugly’ and just attributed the use of cartridges to usual Hollywood sloppiness when it came to such technical detail. Now I see it was a not a flaw. Thanks.