Methods and apparatus are disclosed for sealing a puncture or incision formed percutaneously in tissue separating two internal portions of the body of a living being with an anchor, a sealing plug and a filament connecting the anchor and sealing plug, The methods and apparatus provide for automatic tamping and/or cinching of the sealing plug when the apparatus is withdrawn from the puncture site. The automatic tamping and/or cinching may be facilitated by retracting a procedure sheath without moving the sealing plug or a tamping assembly.