"Most nations used fixed ammunition where the shot was attached via the wooden sabot to the gunpowder charge. The gunpowder cartridge was made of serge or paper. I am not sure as to the construction of Russian Cartridges."
The construction of Russian artillery cartridges was the same: a ball attached to a wooden sabot (called "shpigl", probably from the German term) and powder charge.
"It is interesting looking at the ammunition distribution within a caisson to understand that only the Howitzers were normally equiped with separate powder charges. Range for guns were determined by the elevation and that for howitzers by the powder charge size with a lesser extent to elevation."
The cartridges with shells for the Russian unicorns had fixed amount of powder. The maximum elevation of the Russian unicorns was about 25 degrees. To increase the elevation it was necessary to remove the elevation mechanism.