adjusting rear shocks on a v7 ii ? grub screw

on the lower knurled adjuster on the olle shock, windind down to reduce preload, was really stiff, I noted a allen key grub screw on the adjuster ring, is that a locking screw<hence it was so stiff?, but that would mean a grub screw screwing into a thread which doesn’t make sense as that would damage the thread

from what I remember of my original Olle shocks, the screw did seem to tighten onto the thread. I got rid of them and put some Hagon Nitros on instead, as they have adjustable damping.