Abstract: A caulking gun includes a cartridge-holding component, a trigger assembly, a telescoping extension assembly, and a telescoping actuator rod assembly. The telescoping extension assembly includes an outer tube, an inner tube extending telescopingly within the outer tube, and a compression fitting on the outer tube that is adapted to function as means for securing the inner tube in a desired position relative to the outer tube. The telescoping actuator rod assembly includes a tubular member, a rod extending telescopingly within the tubular member, and a plurality of locking components at spaced apart locations on the tubular member that are adapted to be screwed into engagement of the rod for purposes of securing the rod in a desired position relative to the tube. The outer and inner tubes of the telescoping extension assembly define a plurality of openings at spaced apart locations on the outer and inner tubes that enable access by a user to the plurality of locking components for length-adjustment purposes.