Properly zeroing your red dot sight in 5 steps
A red dot sight helps you acquire targets quickly by showing an illuminated aiming point while both eyes remain open. It does not alter the bore’s line with the stock, and installing one does not automatically sight in a firearm. A proper zero establishes the relationship between the optic’s centre and the point of impact at a specified distance. Getting there methodically prevents guesswork, saves ammunition and builds confidence in every later shot.
Australian shooters usually work in metres, so think in 25 m, 50 m and 100 m rather than yards. A pistol might be zeroed at 25 m, while a general-purpose rifle may use 50 or 100 m, depending on its intended use and ammunition. At a commercial or club range around Melbourne, Bendigo, Ballarat or Geelong, keep the muzzle safe, obey all firing and cease-fire commands, and retrieve targets only when authorised. Ask the range officer about calibre, projectile type and lane rules before firing.
The safety principles are universal, but firearms law is not. Dowagiac Arms is a veteran-owned retailer based in Dowagiac, Michigan, serving customers through its physical store and United States online operation. Australian licensing, permitted acquisition, transport and storage rules are administered through state and territory systems and differ across the country. Controls on suppressors and some firearm components are also strict, so access to a United States online storefront does not mean a firearm or accessory can be imported, transported or used lawfully in Australia.
Understand what a true zero confirms
A zero is tied to one distance, one ammunition load and one firearm configuration. It also assumes a consistent cheek weld, eye position and stock contact. Moving the stock even slightly on a precision rifle can change the relationship between bore and optic enough to move the impact. Treat the rifle, rings, mount, optic and ammunition as a single system, and choose the distance where you need the most accurate hold rather than the most flattering target picture.
Accuracy begins before the trigger is touched. Dowagiac Arms’ solid shooting fundamentals are a useful reminder that a repeatable position, smooth trigger control and balanced follow-through matter more than squeezing a few tiny adjustments out of a loose group. Keep the firearm pointed safely downrange throughout live-fire work and wear the eye and hearing protection required at your range.
Mechanical zero puts adjustable turrets at a neutral reference position; optical zero makes the reticle agree with the bullet at your chosen distance. Many red dots use 0.5 MOA clicks, 1 MOA clicks or mil markings, while some have no adjustment at all. Check the manual rather than assuming that every dot with the same illuminated shape behaves identically.
Set the sight to a mechanical baseline
Begin with the firearm unloaded and stable on the bench. Keep the muzzle in a safe direction, remove the magazine and verify that the chamber is empty before manipulating the sight. Inspect the rings and mount for movement, damaged threads or uneven contact. A loose optic can make a perfect zero impossible to trust, while forcing a damaged turret can turn a small job into a repair.
Place the unloaded firearm in a stable orientation and follow the manufacturer’s lock or release procedure. Set the windage and elevation indicators to their mechanical centre or prescribed baseline, then record the reference marks before movement. Do not use tape, washers, bent mounts or an improvised ring as a substitute for a proper zero-offset solution.
For an adjustable sight, this mechanical baseline is step one. For a non-adjustable dot, the aiming point is repeatable but cannot be dialled: choose a distance appropriate to the optic or use correctly rated, properly installed offset rings. Before proceeding, decide whether the selected zero should prioritise close range, a general set-up or a specific role.
Make a clean baseline group
Step two is a stable, supported baseline group. On the bench or firing point, settle into the same cheek position and stock contact you will use during normal shooting. At 25 m, 50 m or 100 m, fire an initial three-shot group with the intended ammunition. Several Australian shooters call a compact, centred group a decent result; consistency matters more than one unusually tight shot.
Mark the centre of the group, not the centre of the paper and not the best individual hole. Keep the target square, avoid tearing it, and allow range staff to inspect it before crossing the line or retrieving it. If using magnification for identification, retain the same optic setting while recording the zero because a different apparent aim point can cause errors.
Do not chase a scattered first group with turret clicks. Check for a poor rest, canted optic, inconsistent cheek placement, an obstructed lens, an old target, loose mount or unsuitable load. A stable group gives you a centre from which to measure; without one, any correction is based on assumptions rather than evidence.
Apply measured sight corrections
Step three is a measured correction from the group’s centre. At 100 m, 1 MOA is approximately 10.16 cm and 1 mil is 10 cm. If the sight uses one-unit clicks, that click represents roughly 5 cm at 50 m and 2.5 cm at 25 m; a 0.5-unit click is half that amount. Use the sight’s actual markings rather than remembered click values from another optic.
If the group is above the intended point, move the reticle upward so the barrel will send the next group lower. If it is below, move the reticle down. For a group right of centre, move the reticle right so the corrected group should land left; reverse those directions for the opposite error. A useful working rule is to move the sight toward the observed error, then verify the result with fresh shots.
Make one small calculated change at a time. A calculated adjustment followed by another group is more reliable than rapid changes that obscure what occurred. Count clicks from a written starting point, note the new group size and repeat. If the correction does not behave as expected, confirm your units, target distance and reference marks before touching the sight again.
Confirm the zero at its intended distance
Step four is confirmation at the distance that matters. After the close-range corrections look right, shoot another three to five shots at 50 m or 100 m. A close-range zero can hide bullet drop: a group centred at 25 m may sit low farther out. Do not claim a rifle is zeroed for a particular role until it holds its intended point where that role is normally used.
Test with the same load, optic setting, mount and muzzle configuration you expect to keep. Adding or removing a suppressor, changing magazines or altering the stock can move the impact. In Australia, suppressors face stringent legal controls, so a lawful component should never be treated casually or carried across state borders without checking local requirements.
At a club, a repeatable group that supports the centre is often accepted simply as a solid zero. Keep the target dry, verify the reading at the line and record the result before making follow-up shots. If the firearm is intended for general recreational use rather than precision competition, choose a confirmation distance and load suited to its role instead of copying someone else’s settings.
Recheck the zero before it matters
Step five is a maintenance check, not simply a final trigger pull. At the start of later sessions, confirm the mount remains tight and shoot a short verification group at the recorded distance. Re-zero after changing rings, optics, mounts, stock geometry, barrel or ammunition. Temperature and elevation can affect flight enough that long-range precision deserves separate confirmation from a practical red-dot zero.
The result matters well beyond the firing point. Dowagiac Arms’ responsible ownership principles reinforce the need for safe storage, a clear maintenance record and a known sight setting. A firearm secured in an approved cabinet or safe remains unloaded and inaccessible to unauthorised people, while ammunition should be stored in accordance with local law and the manufacturer’s guidance.
Write down the date, firearm, serial number, optic model, ammunition, distance, group size and final reference marks. Screenshots can help, but a permanent range log is better. If a non-adjustable optic can no longer achieve a useful zero, replace the setup rather than improvising. Confirming a red dot’s collimation with the bore is another useful check when performed according to the manufacturer’s instructions.
Make the zero repeatable at the range
Before leaving the firing point, write down the setting that produced your group. At many Australian ranges, a mate will ask what distance and load you are using before trying an adjustment; a clear answer prevents someone from mistaking your deliberate baseline for a fault.
- Record the final reference marks, zero distance, ammunition and group size.
- Inspect the rings and optic for movement before every session.
- Recheck with a short group after mount maintenance or prolonged storage.
- Re-zero after changes to the rings, optic, stock geometry, barrel or ammunition.
- Keep the firearm unloaded while adjusting or cleaning it, and follow local storage and transport rules.
Finish each session by returning the rifle to the safe condition required at the range, cleaning it as directed and putting away only the equipment you have checked. A small target at 25 m is useful for quick confirmation, but it does not replace a full group at the intended distance.
Plan the next session deliberately: download the optic manual, identify the intended zero distance, bring the exact ammunition and ask the range officer for a suitable target and lane. Check the relevant state or territory rules before buying a firearm or suppressor, storing equipment or travelling with it.
When a mount will not hold or a group will not respond to measured corrections, stop adjusting and ask a qualified firearms instructor for an inspection. Book the lane, bring the exact load and a suitable target, and make the first shots confirm the result you came to achieve. That is the practical standard: repeatable accuracy handled responsibly.
