Abstract: A golf swing training device comprising an elongate golf club shaft provided with a golf club hand grip at the upper end thereof and a weighted mechanical head assembly fixedly connected to the lower end thereof. The shaft is connected to the mechanical head assembly by an improved connector assembly. The mechanical head assembly comprises a spring biased weighted cartridge member positioned within a barrel housing and provided with snap ring-engaging fingers extending outwardly through slots provided in the barrel housing. The barrel housing is provided with an adjustable head closure member at the lower end thereof which is adapted to selectively increase or decrease tension of the cartridge-engaging main spring contained in the barrel housing. A cartridge-engaging main spring is positioned within the barrel housing by use of upper and lower locator bearings.