Insertion tool for a medical closure device for the sealing of an opening in a wall of a bodily organ, comprising a tamping force source adapted to deliver a first member to a position at the opening on one side of the wall subsequently to a second member being positioned at the opening on the opposite side of the wall. The tamping force source, which is energized prior to the tamping procedure, can be for example a spring, an elastic band or a pressurized gas container. A tamping spring can be compressed or extended upon loading. The tamping force source can be released in response to a manual operation or be triggered by retraction of the insertion tool.