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How to Reset a Scope to Factory Zero – Simple Tips

Have you got the best scope for your 300 win mag but do not understand how to reset a scope to factory zero? This is as easy a job as it could be. You just have to know how to center the reticle back to where it came from, the zero.

By resetting, we actually mean here setting it to the default of the scope when nothing had been done or tested with it. Of course, there are reasons to do this, and we know just how to meet your inquisitiveness.

Why do you need to center the optic?

Is there actually any slight advantage of zero-locking or resetting a scope to its factory settings? Don’t think this is a stupid question to ask about scopes. You could be a novice, someone that knows how to rough zero using a bore sight and have things pretty close to the mechanical zero. But if the turret is locked at zero, why would you want to reset it? It is to help you make a visual reference. Suppose you have a ballistics chart geared to the load. This lets you visually confirm the adjustments. Also, it makes it easier to go to the original zero.

It is also needed if you use your one scope on different platforms. Different barrel lengths on various rifles and their calibers affect how the scope needs zeroing. So there’s a considerable variation in your degree of scope adjustments.

Finding yourself running out of wind age adjustments and elevation when you attempt to zero the weapon is also a reason to do a factory reset. Centering the optic maximizes your adjustments. The better the adjustments, the farther you shoot, and the more you learn about precision.

Common troubleshooting issues such as a “jumping reticle,” the over multiplied turret adjustment, and the failure of your optic to hold a zero are reasons you should do the factory reset to zero.

Two methods to reset a scope to factory zero

Here are two ways you can try on your scopes. But before attempting any of the easy ones, remember to unmount your scope from your rifle. It is safer and easier and a better way to verify everything.

The Mirror Method

To apply the mirror method, you will need the obvious thing, the mirror itself and a lit room. For optics that have a permanently on and illuminated reticle, this method does not work. Because the illumination will make things different by reflection.

If your scope has an attached sunshade, and you should be able to open the lens cover, at least. If you can somehow remove the sunshade, do that. To maximize efficiency, you have to let the scope flush against the mirror. Setting it against the mirror, you can look through the scope. You will see the crosshairs now. When you have a centered reticle, you will only see the reticle. If it is not at the optical center, you will only see a shadow of the reticle in reflection. At this point, you have to try and line the reflection of the reticle with the reticle itself. Simply adjust the windage and elevation turrets. Keep adjusting till the shadow mingles with the actual.

So what you need to do is:

Set your scope flush against the mirror.

Align the shadow of the reticle with the actual reticle.

The Counting Method

This takes up more time, but guess what, you can do it anywhere you want, even if your room is dark and you don’t have any mirrors. Here, you have to spin the elevation and windage one after the other, one at a time. You can start with anyone of them, but whichever it is, you need to center it first fully. In one direction, spin the turrets as far as you can, but don’t overturn. How to know if you are overturning it? Just stop at the point you feel resistance. At this point, turn the same turret in the opposite direction, keeping count of the clicks. And, hen you reach the end of the rotation, divide your number of clicks by two and now turn it again in the direction you started first with. It would be best if you were optically centered now.

So what you did was:

Turned your elevation or windage turret as far as you could.

Stopped at the resistance and counted clicks in the opposite direction.

Made it half and turned forward again by that number.

When do I need to reset it to factory zero?

If you want to swap the scope you among the rifles you own, you will need to reset it to factory zero. If you bought yourself a second-hand scope, then you also need to do a factory reset. For firearm you are newly using or using after a break, you will need to do this.

Is it different with the scopes I own?

It may because scopes are built differently from each other. So how you reset the factory zero for each of them should be different. But don’t worry because you won’t need more than wrenches or screwdrivers. It should be easy.

How necessary is it to slip the scales?

Very. Use a screwdriver or wrench for that.

How long does it need to do the resetting to zero?

Not more than a couple of minutes.


Hopefully, you actually have learned a thing or two about resetting your scope to factory zero, and we are glad we could help. But remember, no matter how professional you are, it will never be as precise as the factory one, even though we call it a factory reset.

We can only reach the approximation. And the best part is, the steps aren’t too hard. One might say there is math, which is annoying, but it is a simple division by 2. If you can’t do that, all you will need is a calculator as an extra. Otherwise, you should be able to do things for yourself!

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