Scope Adjustments - Understanding How Your Scope Works
Having the best scope in the world doesn't mean anything if you don't understand how to use it properly and what the adjustments are and what they do.
In this article we will cover the three most common adjustments found on most scopes. We will be using a tactical style Leupold Mark 4 scope for discussion in this article.
The three most common adjustments are:
Parallax (some scopes may have parallax already set at the factory which can not be adjusted)
Before we begin it's important to note that most scope turret adjustment increments will either be in - inch or - MOA (minute of angle - 1 MOA is 1/60 of a degree in a circle of 360 degrees) increments. Consult your scope manual to determine whether your scope is in MOA or inches and whether each "click" of the scope turret is in - increments. Some scopes will have adjustments in 1/8 increments.
The windage adjustment is found on the right of your scope. (see photo below)
The scope shown in the photo below has - MOA adjustment increments. This means that each "click" is - minute of angle, which translates into an adjustment of 29mm at 100M or - of an inch at 100 yards. This means that your point of bullet impact will change each time you make an adjustment to your scope. Your scope should be clearly marked as to which direction to turn the turret to make the desired adjustment. For example, say you place a few shots and it turns out that your rifle is shooting an inch to the right of your point of aim. This means that you would turn your windage turret three clicks in the "left" direction. Your scope will also give you an indication on which way to actually turn the turret to move your point of bullet impact in the desired direction.
The elevation turret operates in the same way as the windage turret except this control will adjust the "up and down" movement of your point of bullet impact. Again, look at the markings on the scope to determine which way you should adjust the elevation turret. Your elevation adjustment will be found on the top of your scope body.
Finally, another feature on more of your high end tactical scopes is a parallax adjustment.
An official definition of parallax is:
Parallax is the apparent movement of the target relative to the reticle when you move your eye away from the center point of the eyepiece. It occurs when
the image of the target does not fall on the same optical plane as the reticle.
This can cause a small shift in the point of aim.
Most scopes will be parallax free out to 100 yards or so. Don't let it concern you if your scope does not have a parallax adjustment, as the effects of parallax under normal (e.g. non extreme range shooting) are very minor.
However, where very precise accurate shots are required, a scope with a parallax adjustment is a must. To adjust the parallax settings, follow these steps. First, your scope reticle should be clear and crisp on the object as you sight down your scope. Next adjust the parallax adjustment turret while you move your head up and down slightly. Keep adjusting the parallax adjustment until there is no movement in the reticle in relation to the target.