I have created a full 3d printed pump kit for the Nerf Retaliator. This is still under construction. At this point the priming arms are too thin and will need to be made wider to improve their rigidity and provide more clearance for the screw securing the arms to the shell.
You will need to mirror the priming arm in your slicing program in order to print both sides. The slider will require supports.
You will need 4x 4M 8mm countersink screws and 4x 4M nuts.
Please mod and Nerf responsibly!