Goodcheer: I think what you may be thinking about are combustible cartridges. As soon as Colt invented his revolver he was also working on this type of ammunition. The idea was to have a self contained unit of powder and ball that could be quickly loaded in a percussion revolver.
The big concern was residue and fouling left in the chamber, this material- if not fully burnt up- could hold an ember. If a soldier loaded another round on top of this ember the new round would explode and probably kill the soldier.
Incredible as it may seem, the original form of this ammunition did not use paper, very thin German tin was used for the case. A powder charge was placed in this case and then a conical bullet glued in place. The blast of the percussion cap was powerful enough to rupture the tin case and explode the inside powder.
A lot of shooters today think you are suppose to tear open the case to expose the powder before loading. This is wrong and it negates the purpose of the tin. The tin was fireproof. If there was a live ember left in the chamber the tin of the new case would protect the powder charge.
The tin was also waterproof. The military had really tough tests- submerge the ammunition for four hours and then test it. If a certain percentage of the ammunition would not fire, then the military would not buy it. There was some Johnson & Dow ammunition that often failed this test.
In any event Colt was the main supplier but was having trouble getting the German tin. It was the only tin that really worked well. Colt then came up with the idea of a paper/linen case but these cases would be kept in a shellaced container that was waterproof. The miliary said that would be okay and the paper/linen type cases came into existence.
D.C. Sage of Middleton Connecticut was another major supplier. He used a fish gut case that would "crisp" when fired.
Generally, the military used ONLY these type cartridges in revolvers. I have tried to find evidence of cavalry units issues flasks for pistols, as well as loose balls- I'm not saying it was not done but if it was done- it was very rare.
Terry White of Gettyburg, PA is the expert on this topic. He writes for collectors of this ammunition but we shooters can derive benefit from reading his books. There is a lot of information available on this topic.
Check this:
https://www.gunshowbooks.com/cgi-bin/webc.exe/st_prod.html?p_prodid=GS37843&sid=ED3w00Yh