Abstract: A combined caulking tube plunger and enclosure assembly is disclosed which includes a single piece of drawn metal in generally a cup-shaped configuration including a bottom wall, a circular or annular side wall which forms a close fit with the inside diameter of a caulking tube and which provides guidance of the plunger portion through the caulking tube, and an outer rim which is adapted to be rolled over the outer end of a caulking tube to form a closure and seal therewith. A circumferential break-away score or dart is formed in the side wall axially inwardly of the rim which causes the major portion of the side wall and the bottom wall, forming a plunger, to be broken away from the rim upon the application of force by the ram of a caulking gun thus to separate the plunger portion from the rim portion.