By installing a rapid fire circuitry, and even learn a fantastic paint job. This project guides you through the build process cranking it up to 500 RPM and attaching a round counter.

This will be requiring cranking up your nerf guns to be able to connect the battery packs. They even used a ball point pen to slide it on the gun.

Now if you want to add an LED round counter you need to solder the counter solder leds from their locations on the circuit board to push button switches that were mounted on the gun. Then dremel part of the chain-gripping assembly to mount the roller switch.