Dating sites for target shooter
If the target is focused either ahead or behind the reticle, then the target will appear to move with relation to the reticle. There is no parallax when your eye is in line with the scope's optical axis.To check for parallax, move your eye side to side, then up and down (bob and weave your head), and adjust the focus/parallax turret until the movement in the scope disappears.
I highly recommend the March benchrest target scope.The Leupold Gold Ring competition rifle scope is my favorite.The windage and elevation adjustments are smooth to turn but still have a positive detent.For windage and elevation adjustment my scopes have 1/8″ MOA movement per click—meaning I turn the turret eight detents to move the bullet's Point of Impact (POI) on the target by one MOA (one inch at 100 yards, two inches at 200 yards, etc.) This is appropriate for a short-range target scope, but would be impractical (too fine an adjustment) for long-range shooting.The parallax adjustment focuses the target image onto the same plane as the reticle.