How to zero a rifle scope: a step-by-step guide
A practical guide to zeroing a rifle scope: choosing a zero distance, bore-sighting, confirming on paper, and adjusting the turrets from a group using your scope's click value.
What “zero” means
Your zero is the distance at which the bullet's path crosses your line of sight so that point of aim equals point of impact. Every other number on your range card — drop, elevation, holdover — is measured relative to that zero, so a sloppy zero puts an error into every shot you take afterwards.
Choose a zero distance
| 100 yd / 100 m | The standard for precision and target work. Simple, repeatable, and it makes your dope chart start cleanly from zero. Recommended unless you have a specific reason not to. |
|---|---|
| 200 yd | Common for hunting flat-shooting cartridges — it keeps the bullet within a couple of inches of the aim point from the muzzle to beyond 250 yards (“maximum point-blank range”). |
| 25 yd | Useful for air rifle or indoor ranges for small calibre firearms. |
Whatever you pick, set the same value in the calculator's Firearm section so the predicted trajectory matches your rifle.
Step by step
- Mount the scope properly first. Correct eye relief, level reticle, ring screws torqued. A zero is only as stable as the mount.
- Bore-sight to get on paper. Remove the bolt, rest the rifle steady, look through the bore at a target, then — without moving the rifle — adjust the turrets to bring the reticle onto the same spot. A laser bore-sighter or collimator does the same job.
- Fire a group, not a shot. Shoot 3–5 rounds from a stable position at your zero distance, letting the barrel cool as needed. One shot tells you almost nothing; the centre of a group is the real data.
- Measure from group centre to point of aim in the direction you need to move the impact — e.g. “2 inches low and 1 inch left”.
- Convert the miss to clicks (see below) and adjust. Turret direction arrows show which way moves impact up and right.
- Confirm with a fresh group. Repeat until the group centre sits on the aim point. Then fire one more group to verify it holds.
- Reset the turrets to zero (lift-and-turn or set-screw collars) so you can always return to your baseline after dialing.
Turning a miss into clicks
You need your scope's click value. The two common ones:
- 0.1 MIL per click ≈ 0.36 in at 100 yd (1 cm at 100 m)
- 1⁄4 MOA per click ≈ 0.26 in at 100 yd
Divide the miss by the distance value, then by the click value. Example: 2 inches low at 100 yards with a 1⁄4-MOA scope → 2 ÷ 1.047 ≈ 1.9 MOA → about 8 clicks up. At 200 yards the same 2-inch miss is half the angle, so half the clicks. If you would rather not do the arithmetic on the line, the group analysis tool reads the correction straight off a photo of the target.