Every scope I've checked when set to optical zero (reticule's dead center on the scope tube axis) has more clicks in one direction than to the opposite thereof.
With the rifle clamped in a bench vise, loosen the rings just enough to let the scope turn in them. Look through the scope then adjust the knobs until the reticule stays in one place on some distant image. Then loosen the knobs' lock scew, rezero them and tighten their lock screws. Test the scope again for its optical zero and readjust if needed.
After doing this, it's easy to see how much each adjustment has to its mechanical stops inside the scope.
Best thing about putting a scope's adjustments to optical zero is after mounting one in rings attached to their bases, bore sighting gives one the difference between the receiver axis and the mounted scope's optical axis. It's common to see several MOA difference. If they're well aligned to start with, you've got 20 MOA of up adjustment from bore sight if that's what there is to the stop for elevation. Common with well aligned scopes with a 40 MOA total adjustment.