I can't seem to be able to let go of the idea of using the sand auger in a rocket. Here it is adapted to the body of my existing Spikor and with a G75M loaded. It appears I would need a -4 delay.
Update: Here, the screw section is modeled as a solid object. I still have no idea if the screw section will help or hurt stability. Adapting the auger to this rocket won't damage either so I think I'll build it.