I recall reading, many years ago so it may have been Elmer Keith, that the cap and ball sixguns were regularly used into the mid 1880s.
The reason given was that their ammo was very cheap compared to cartridge guns, and cartridges might not always be available. But you could generally count upon finding caps, bar lead and gunpowder in town.
This basically echoes what other posters here suggested.
The local blacksmith, for a minor fee, could cast a few hundred balls and conicals if you supplied the lead and bullet mould.
As for my name ... Gatofeo means "ugly cat" in Spanish. The origiin of the family name remains clouded.
I've traced the Gatofeo family history back as far as the ancient Roman Empire, to the reign of Gatofeus the Questionable.
During the middle ages there was a teutonic knight by the name of Gatofeo the Timid, whose stirring battle cry was, "You go ahead! I'll be along in a bit!"
Yes, through the ages, the family name of Gatofeo has been at the forefront of history.