How to adjust a rifle scope
Quick answer: a rifle scope has up to four adjustments. The elevation turret (top) moves impact up and down and the windage turret (right side) moves it left and right, always turn them the direction you want the shots to go. The magnification ring (rear) changes zoom, the side-focus parallax knob (left side, if fitted) sharpens the target at range, and the diopter (eyepiece) focuses the reticle to your eye. Turrets click in 1/4 MOA or 0.1 mil; each click moves impact a set amount at 100 yards.
The two turrets: windage and elevation
These are the only adjustments that change where the bullet lands. The elevation turret sits on top and moves your point of impact up and down; the windage turret sits on the right side and moves it left and right. The golden rule is simple: turn each turret in the direction you want the shots to move. If your group prints low and left, dial UP and RIGHT. The caps are marked with a "U" and an arrow for up, and "R" for right, so you can match the label to the correction you need.
Reading the clicks: how far each one moves impact
Turrets adjust in fixed steps you can feel and hear. Most hunting and tactical scopes click in 1/4 MOA (about 1/4 inch at 100 yards) or 0.1 mil (about 0.36 inch at 100 yards). Those values scale with distance and shrink up close: at 200 yards a 1/4 MOA click moves impact about 1/2 inch, and at 25 yards only about 1/16 inch, so near targets need roughly four times the clicks. If the MOA-versus-mil part is new, our MOA vs MRAD guide breaks it down. To turn these adjustments into a zero at the range, follow how to sight in a rifle scope.
The magnification ring: the numbers on your scope
The ring near the rear changes zoom. On a 3-9x40 scope, the 3-9x is the magnification range and the 40 is the objective lens diameter in millimeters. Turn the ring up for more magnification when the target is far or small, and down for a wider field of view and faster target acquisition up close. On a second-focal-plane scope the reticle stays the same visual size as you zoom; on a first-focal-plane scope it grows and shrinks with the image (see FFP vs SFP).
The side-focus parallax knob (if your scope has one)
Higher-magnification scopes add a third knob opposite the windage turret. It is the parallax adjustment: turn it to your target distance until the image is sharp and the reticle stops appearing to float against the target when you shift your head. It does not move the bullet; it removes aiming error and sharpens the picture. Fixed-parallax hunting scopes skip this knob and are preset, usually at 100 yards (150 on some models).
The diopter: focusing the reticle to your eye
The ring on the very back eyepiece is the diopter, and it focuses the reticle, not the target. Point the scope at a plain bright background such as the sky, glance through it for only a second or two, and turn the diopter until the crosshair looks crisp. Set it once for your eyes and leave it alone. People often confuse a blurry reticle (a diopter problem) with a blurry target (a parallax or focus problem); they are two different knobs.
Common mistakes when adjusting a scope
- Turning a turret the wrong way: dial toward where you want the impact to move, not away from it.
- Forgetting the distance math, so corrections at 25 or 300 yards are off by a factor of the click value.
- Using the diopter to sharpen the target (that is the parallax knob's job) or vice versa.
- Chasing single shots instead of adjusting to the center of a group.
Always follow safe firearm handling and your local range rules. This is general guidance, not professional instruction. When in doubt, get hands-on help at a range.
FAQ
Which way do I turn a rifle scope turret?
Turn the turret in the direction you want the point of impact to move, and the turrets are marked to help: "U" or an arrow with UP raises impact, "R" or RIGHT moves it right. So if your group is low and left of the bullseye, you dial UP and RIGHT. Most turrets also click that direction as printed, so match the label to where you need the shots to go.
How much does one click move the bullet?
It depends on your turret value and the distance. A 1/4 MOA turret moves the point of impact about 1/4 inch per click at 100 yards (1/2 inch at 200, and so on); a 0.1 mil turret moves it about 0.36 inch per click at 100 yards. At 25 yards each click moves impact only a quarter of its 100-yard value, so it takes about four times the clicks.
What do the numbers on a rifle scope mean?
The two numbers describe magnification and objective size. On a 3-9x40, the 3-9x is the zoom range (3x to 9x magnification) and the 40 is the objective lens diameter in millimeters. A bigger objective gathers more light; a wider zoom range covers more situations. The magnification ring at the rear of the scope changes the first number.
What is the side knob on my rifle scope for?
That third knob, opposite the windage turret, is the side-focus parallax adjustment. It sharpens the target and removes parallax error (reticle appearing to float on the target when you move your head) at a given distance. Turn it to your target range until the image is crisp and the reticle stops shifting. Scopes without it have a fixed parallax, usually set at 100 or 150 yards.
How do I focus the reticle so it looks sharp?
Use the diopter, the ring on the very back eyepiece. Point the scope at a plain bright background (like the sky), glance through it briefly, and turn the diopter until the reticle (not the target) looks crisp. Set it once for your eyes and leave it; it focuses the reticle, not the target, which is what the parallax knob is for.
Related: how to sight in a rifle scope · MOA vs MRAD · what is parallax · best rifle scopes 2026.