Method of manufacturing a firework rocket, wherein the firework rocket comprises - a casing that has - a bottom portion; - a cap portion; - a main portion that connects the bottom portion to the cap portion and surrounds an internal space of the casing; - at least one effect kit that is arranged in the casing internal space; wherein - a shell is provided that comprises - a first end portion that surrounds a first opening of the shell - a second end portion that surrounds a second opening of the shell; - a main portion that connects the first end portion to the second end portion and surrounds an internal space of the shell; - at least one of the effect kits is filled into the shell internal space through the first opening and / or through the second opening; - the bottom portion is shaped from the first end portion - the cap portion is shaped from the second end portion; - the filling takes place before the bottom portion is shaped and / or before the cap portion is shaped; characterised in that - the filling takes place through the first opening and / or through the second opening if the filling takes place before the bottom portion is shaped and before the cap portion is shaped; - the filling takes place through the first opening if the filling takes place before the bottom portion is shaped and after the cap portion is shaped; - the filling takes place through the second opening if the filling takes place before the cap portion is shaped and after the bottom portion is shaped. - a casing that has - a bottom portion; - a cap portion; - a main portion that connects the bottom portion to the cap portion and surrounds an internal space of the casing; - a bottom portion; - a cap portion; - a main portion that connects the bottom portion to the cap portion and surrounds an internal space of the casing; - at least one effect kit that is arranged in the casing internal space; - a shell is provided that comprises - a first end portion that surrounds a first opening of the shell - a second end portion that surrounds a second opening of the shell; - a main portion that connects the first end portion to the second end portion and surrounds an internal space of the shell; - a first end portion that surrounds a first opening of the shell - a second end portion that surrounds a second opening of the shell; - a main portion that connects the first end portion to the second end portion and surrounds an internal space of the shell; - at least one of the effect kits is filled into the shell internal space through the first opening and / or through the second opening; - the bottom portion is shaped from the first end portion - the cap portion is shaped from the second end portion; - the filling takes place before the bottom portion is shaped and / or before the cap portion is shaped; - the filling takes place through the first opening and / or through the second opening if the filling takes place before the bottom portion is shaped and before the cap portion is shaped; - the filling takes place through the first opening if the filling takes place before the bottom portion is shaped and after the cap portion is shaped; - the filling takes place through the second opening if the filling takes place before the cap portion is shaped and after the bottom portion is shaped.