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How To Reset A Scope To Factory Zero On Your Rifle?

How To Reset A Scope To Factory Zero On Your Rifle?

Buying a new rifle and scope is rendered completely redundant when these two precision tools are used separately. Or are not calibrated with each other and used in tandem to guide the bullet to the mark. 

This calibration of the rifle and scout scope to its optical centre by resetting the turrets, to ensure that the aim is accurate, is called zeroing. You would also need to re-centre your scope every time you remove it, swap scopes with rifles or buy a new scope for your rifle.

How To Reset A Scope To Factory Zero On Your Rifle

While most experienced shooters and hunters have learned the process of zeroing a rifle by trial and error method, others borrow mechanical techniques from these avid shooters and pass on the information to other novices. 

However, it is important to know that there is no right or wrong way to calibrate the rifle scope with a particular firearm, the procedure which feels the most natural to the shooter and gets the job done is the most important method. 

To get accurate shots and save ammunition, one should learn to properly mount, sight and adjust a rifle scope to its zero reset point.  When a scope is optically centred, it allows you to maximize the number of adjustments you can make on your elevation and windage turrets, thus maximizing how far and how precise you can shoot in long-range shooting.  

Given below are the basic steps that you must follow to zero lock your scope at your target for visual reference so that you can precisely hit what you are sighting in and not miss the bullseye.

Installing the Scope:

Installing the Scope

Mounting the Scope on the Rifle: The first thing that one must do is to mount the scope onto the rifle properly. Use a good quality base mount and scope rings so that the scope will be held sturdy for many years. 

For that, you need to first prep the rifle to make sure that the scope mount fits snugly and perfectly on the base. Then clean the holes of the four receiver screws with a q tip and rubbing alcohol to ensure that no dirt is present that can cause the scope base to not fully sit onto the rifle. 

Then secure the scope and level it with reference to a scope bubble level. Screw the scope base properly to the rifle mount after dry fitting the scope and see how you would want your forward mount to sit. After that, attach the scope rings and scope correctly with a torque wrench. 

Make sure that the side of the scope with the logo of the manufacturer is placed opposite to the ejection port. Finally firmly fasten the screws with a thread lock formula.

Precise setting of the eye relief

Before attaching the scope to the scope ring permanently, the user needs to adjust the eye relief of the scope to prevent the black ring that can sometimes be seen around the edge when looking through the scope at the target. 

In order to get the perfect eye relief and proper calibration of the scope, place the rifle on your shoulder as you would do in the field. Adjust the position of the scope such that the black ring is removed from the sight of view and edge to edge clarity is achieved. Then tighten the scope rings permanently. 

Proper levelling of the crosshair: After finding the correct position for your eye relief, you need to level the reticle of the scope to confirm accuracy and authenticity of the compensation of windage and elevation and the crosshair position. 

Setting the Zero:

Setting the Zero on a scope

After heading to the range and sighting in the gun by placing it on rest, the scope should be set to zero. You will need to load the rifle, take three to five shots, and then examine your shot groupings before setting zero. Also, you must centre the optics from multiple distances and different positions.

Optical centring of the scope can be done in two ways, the mirror method and the counting method.

Mirror method: For this method, you would need a mirror and a well-lit room. Thus this method can only be used in the shooting range. Remove the scope’s sunshade, if present, and set the scope flush against the mirror. 

Aim the rifle towards a brightly lit background. Setting the scope against the mirror, look through it where you will see the crosshairs now. If the scope is optically centred, the only actual reticle will be visible, but if it is not, there will be a shadow of the reticle hovering at the centre along with the markings of the actual reticle. 

Adjust the turrets till the markings of the actual reticle line up with the shadow. Once the actual reticle and the shadow are aligned, your scope will be zero reset.

Counting method: Unlike the mirror method, this takes up a lot of time. However, the advantage of this procedure over the mirror method is that you can reset the scope in a dark environment and without any mirror. 

Thus if you are present in the shooting range during the evening and you are out on a nighttime hunting expedition, you could easily zero-reset your turrets without any problem.

Firstly, you need to centre the elevation and windage fully in accordance with the rifle and then turn the elevation and the windage turret of the scope to the maximum position in one direction. 

This rotating should be stopped when you feel resistance. Now, start turning the turret in the opposite direction and count the number of clicks as you turn. Divide this number of clicks by two and then start rotating the turret in the same direction you rotated the first time.

Do the above steps till the number of clicks that you got by halving the initial number. Once you do that, your scope will be optically centred and set to zero.

Making Necessary Adjustments:

Ocular focusing and boresighting of the new scope: Before sighting in the new scope you would be needed to dial in your ocular focus to have a crisp, error-free and bright image of the scope’s reticle. 

Then, line up your rifle by aiming it towards a high contrast background keeping a good sight picture and your eye at the required distance from the scope. After that, adjust the scope’s diopter until your reticle is clearly in focus and in line with the crosshair.

Setting the adjustment knobs with accuracy: Most scopes have two dials on it, the windage and elevation knobs, which are used to adjust and sight in your scope. So that what you are seeing through the scope and where the rifle is aimed will be in line. 

The top knob, the elevation adjustment knob, is used to adjust the up and down of the crosshairs, and the one on the side, the windage adjustment knob, will adjust the scope left to right. On most scopes, the knobs can be twisted with the hand and finger adjusted like a dial.

Making the adjustments small and precise: Most scopes come with a ¼ MOA click rate, i.e.,  with each click you turn either dials, the reticle moves the zero 1/4 inches. 

You must always read the user manual that comes with your scope on the first hand to be sure about the adjustments. 

Slipping the scale: This is the process by which the optic’s scales are brought back to zero in order to indicate rifle data with no windage and elevation correction. This is an essential step in zeroing the scope. 

You should use a screwdriver or an Allen wrench to adjust the turret caps and thus, the adjustment scale, to match the mechanical zero on the scope. 

Some things you need to keep in mind while zeroing are that incorrect parallax or optical focus will change your zero significantly. Also, you need to adjust the turrets keeping yourself in your most comfortable position as changing your body position will change your zero.


Now that you have learnt all the steps necessary for setting the zero in your scope with reference to your rifle, we hope you would not have any troubles in the shooting range or while hunting. 

Also, it is important that you do not hurry while doing the steps and complete them with utmost care and precision as a sudden upheaval in posture or a slight movement while setting the turrets can disrupt the whole set up.

Optical centring a scope is not a very complex process and can be done within a few minutes. You also do not require as many tools for this process as needed while mounting the scope on the rifle. 

You would only need a screwdriver or an Allen range for slipping the scale of the scope. However, it is foremost to remember that though it is called a factory zero, no matter how skilled you are, the resetting will never be as accurate as when it came packaged straight from the factory.