Rule 4403. Motion for new trial or to confirm or reject or grant other relief after reference to report or verdict of advisory jury. Upon the motion of any party or on his own initiative, the judge required to decide the issue may confirm or reject, in whole or in part, the verdict of an advisory jury or the report of a referee to report; may make new findings with or without taking additional testimony; and may order a new trial or hearing. The motion shall be made within fifteen days after the verdict or the filing of the report and prior to further trial in the action. Where no issues remain to be tried the court shall render decision directing judgment in the action.