Which blackpowder is considered the most common type for cap and ball revolvers?

The most common type of black powder for cap and ball revolvers is FFFg. This specific granulation is fine enough to provide a quick and efficient burn rate suitable for the smaller caliber revolvers typically associated with this style of firearm. The finer grains of FFFg allow for better packing density in the cylinder, leading to improved accuracy and consistency in firing. Additionally, it helps to create a quicker ignition response when used in conjunction with percussion caps, which is essential for reliable operation of cap and ball revolvers.

Other types of black powder, such as FFg or Fg, are generally used for different applications. FFg, while also suitable, is more commonly employed in larger caliber firearms like rifles. The Fg type is coarser and is best used for very large caliber guns or cannons, which do not require the rapid ignition that FFFg provides. The mention of "Expense Powder" is not relevant as it does not correspond to a recognized classification of black powder for firearms.