While the directions for the measure indicate the parts of a return spring and "F" lever, they are not included when the measure comes as part of a progressive press kit as they are not applicable. The return spring and "F" lever are needed only when using the measure in conjunction with the Turret press. We recommend the use of the chain in conjunction with the Auto Disk on progressive presses. Using the chain as a way to reset the measure almost eliminates the chance of a double charge because the carrier of the press has to get to the bottom before the chain resets the measure. At the bottom of the stroke, the index system moves the case to the next station so it's chance of coming back up for another charge is almost impossible.
To correctly install the Chain, loop the chain through both holes in the Auto Disk lever (pass the end through the hole closest to the measure, then pull the remainder of the chain through the hole close to the end of the lever so most of the chain hangs down). The chain should be taught with the carrier in the down position. Using the small spring as a buffer on the bottom of the carrier and the bell housing on the end of the chain, raise the carrier so that you can pull one bead more through the powder measure lever. This way, you can be assured that the chain has the proper tension. If the buffer spring is not used in the manner described, chances are great that the chain would break.
A video on how to install the Chain correctly can be found through this link.