The Fine Elevation Adjustment Screw on the Viper's Rest is just that.

It's Not a speed screw. If you need to move up and down that far and that fast, then you're not on target to begin with!

The Viper's fine elevation adjustment screw gives you precise movement up and down. We accomplish this by turning the hardened, pointed insert concentric with the body of the screw. It can't do anything else but go straight up and down. The threads on the screw are cut as close to an interference fit as modern machining can accomplish. The screw is custom mated with a machined brass insert, that goes thru your Aluminum Base Plate. Brass on Brass and a small amount of clear grease and you're set to go.