An apparatus for connecting bars includes a clip string, a barrel having a clip receiving cavity, with a terminal clip of the clip string received in the clip receiving cavity. A drive is received in the barrel and extends proximally from the barrel. The drive includes a hammer received in the barrel. The hammer reciprocates longitudinally within the barrel for contacting and expelling the terminal clip from the barrel. A cam guide is connected to the drive. A cam plate having a cam track is pivotally connected to the barrel. The cam guide engages the cam track such that the cam plate pivots back and forth as the drive is moved distally and proximally relative to the barrel. At least one finger is connected to the cam plate such that the finger engages and advances the clip string end of the clip receiving cavity as the cam plate pivots back.