Is this similar to the range rod method, or is this a spring loaded dead center basically? Hard to tell exactly how it is supposed to be used, not a great description on their website.
I would guess its used to center the barrel in the headstock when the headstock is too long to allow the barrel to extend all the way through. I would think it would be used with a bushing on the outboard side of the spindle. Just a guess on my part but I cant see another use for it based on the picture