If the “mortar rack” is a preloaded pyrotechnic device containing multiple tubes that is discarded after one use, then it is considered a “cake” in Finale 3D terminology. Pyrotechnic effects like cakes are created from the Effects menu on the main menu bar.
If the “mortar rack” combines a standalone piece of equipment that can be reused over and over along with shells that are loaded into the rack, then rack itself and the shells are created as separate items in Finale 3D. The mortar rack equipment is created from the Racks menu (Finale 3D Hobbyist and Pro only) and pyrotechnic effects including shells are created from the Effects menu.
