An active feed paintball loader for supplying paintballs to a paintball marker. The loader includes a container for storing a plurality of paintballs. An outfeed tube on the container is connected to an inlet tube on the marker. The loader further includes a drive shaft, a feeder rotatably disposed in the container for feeding paintballs into the outfeed tube, and a drive spring having first and second ends. The first end is engaged to the feeder to provide a driving force to rotate the feeder within the container. The second end is coupled to the drive shaft. The drive shaft operates to wind the drive spring to maintain sufficient tension on the drive spring to maintain a paintball stack in the outfeed tube. The loader further includes a mechanical drive handle accessible externally of the loader and connected to the drive shaft to manually wind the drive spring.