How To Reset A Scope To Factory Zero (Mirror Method)

scope factory zero

A scope factory zero, set by manufacturers, aligns the scope with the rifle’s bore at production. Your rifle scope is zeroed when the crosshairs of the scope are adjusted to be perfectly aligned with the rifle so that when the gun is fired, the bullet will travel exactly where the crosshairs are pointing. Most scopes come with a pre-set factory zero.

To reset a scope to this factory zero, shooters need to adjust the scope’s windage and elevation turrets back to the original factory settings. Getting your scope back to factory zero is very important for offering a reliable starting point for personalized adjustments. Shooters utilize factory zero when adapting the scope to a new rifle or correcting extensive deviations from original settings.

However, many shooters start making adjustments right after unboxing their brand-new optic, only to find they have lost zero! In this post, we’ll teach you exactly how to reset a scope to factory zero.

Step Instruction Additional Notes
1 Ensure the firearm is unloaded and safe to handle. Safety is paramount. Always check the chamber.
2 Remove any lens caps and adjust the scope to its maximum magnification. Maximum magnification provides a clearer view for adjustments.
3 Set up a target at a known distance (commonly 100 yards/meters). A standard distance helps in accurate resetting.
4 Secure the rifle in a stable rest or gun vise. This prevents movement and ensures precision.
5 Fire a group of shots (usually 3-5) at the target. Multiple shots confirm consistency in aiming.
6 Inspect the target and mark the center of the shot group. This identifies the actual point of impact.
7 Adjust the windage and elevation knobs accordingly. Turn the knobs to align the crosshairs with the marked center.
8 Repeat firing and adjusting until the point of aim aligns with the point of impact. This may require several iterations.
9 Once aligned, reset the scope’s windage and elevation dials to zero. Refer to the scope’s manual for specific procedures.
10 Confirm the zeroing by shooting another group. Ensure the adjustments are accurate.
11 Replace any lens caps and clean the scope as needed. Proper maintenance extends the life of the scope.

What Is A Factory Zero?

A factory zero is the initial windage and elevation settings on a rifle scope. The factory zero of a gun scope is established by the manufacturer during production. Scope manufactureers create a factory zero with the rifle’s bore under controlled factory conditions. However, this generic setting might not suit all shooters due to varying factors like individual shooting styles, ammunition types, and environmental influences.

When you first purchase a night vision scope to hunt coyotes, you might be eager to start making adjustments. Shooters after play with the windage and elevation adjustments to try and get an understanding of their new scope. However, this is a quick way to lose your factory zero.

Factory zero is when both the elevation and windage turret is perfectly centered in the ‘optical center’ of your scope. But, how do I reset my particular scope to factory zero?

picture of reticles for a scope out of factory zero

Steps To Reset A Scope To Factory Zero

In order to get your thermal scopes for hog hunting to reset to factory zero, you will need just two pieces of equipment.

  • Your Rifle Scope
  • A Mirror

The mirror method is the best & fastest way to return your scope to factory zero and get the reticle in the correct position. Say you have a 300 Win Mag scope, start by following these steps:

  1. Grab your scope tube and place it against the mirror.
  2. Make sure the front objective is sitting flush against the mirror.
  3. If your scope is out of ‘factory zero’ then you will see a double image of the reticle.
  4. Make adjustments until you see just one reticle and it is optically centered. If your reticle is off horizontally, make a windage adjustment. If your scope is vertically off, make an elevation adjustment. Knowing which way to turn a scope is very important!


Another popular tactic is the counting method. I will say this is probably not as accurate.

  1. Take the caps off your adjustment knobs.
  2. Turn your turrets all the way clockwise or counter-clockwise.
  3. Then slowly turn each turret the opposite direction while counting clicks until you can’t turn anymore.
  4. Divide the number of clicks by 2 to find the optical center.

The truth is that this method can take time. Oftentimes I lose count after just a few clicks! Maybe that is just my poor attention to detail. Regardless, this is an option for a shooter that does not have access to a mirror. It can be tricky to learn how to fix a scope that won t adjust. Resetting to factory zero can help!

Why Is A Factory Zero Helpful?

To some shooters, it might seem odd that anyone would want to set their scope to factory zero. After all, you don’t need to achieve factory zero before zeroing your 450 bushmaster or other types of scopes! I would recommend a 50 yard zero for most hunters.

  1. Used Scopes – If you just bought a used scope from a pawn or gun shop, some shooters may want to reset their factory zero before sighting in their rifle.
  2. Repurpose Your Scope – Another popular reason to factory zero your scope is that you want to replace your optic. If you plan to swap out scopes and use this optic on another weapon, ensuring your scope is optically centered makes things easier.

A Word Of Warning

Just because your scope is set to ‘factory zero’ does not mean it’s calibrated for your need! You will still need to take the time to zero your scope to the particular distance you plan on shooting from.

After mounting your scope, it is important to zero your rifle scope every time you use it, as it ensures that the rifle scope is properly calibrated and that the scope is properly aligned with the firearm.

This is especially important when using the rifle for hunting, as a misaligned scope could cause you to miss the target or even injure yourself.

And if you have a hard time getting your optic zeroed, your scope might be broken! Send it back to the manufacturer if this happens to you.

Frequently Asked Questions

Why can't I zero my scope?

It's possible that your scope rings are not properly tightened. When the rings are loose, the rifle barrel will move around and you will not be able to get a good zero. Make sure to check that the rings and scope mounts are tight and secure before trying to zero your scope again. You can adjust windage and elevation all you want, but it won't center if the scope is loose!

What magnification should I zero my scope at?

The magnification you should zero your scope at depends on the type of scope you are using and the type of shooting you plan to do. Generally, it is recommended to zero your scope at the highest magnification that you plan to use for a given shooting distance. This will ensure the most accuracy when you dial up or down for different distances.

Why does my scope run out of adjustment?

When a scope runs out of adjustment, it usually means that the scope has reached its maximum range of adjustment, and further adjustments are not possible. This can be caused by a number of different issues, such as the scope being too large for the rifle, the scope is mounted in the wrong position, or the scope not having enough adjustment range.

How many inch pounds Should I tighten my scope rings?

You should tighten your scope rings to about 15-18in.lbs of torque. It is important to use the correct size wrench and to always use a torque wrench to ensure you don't over-tighten the screws.

The Bottom Line

Now you know the best method to set your rifle scope to factory zero. There are other options like the counting method & using a laser bore sight, but the mirror method works best! Remember, make adjustments in just one direction at a time until you have your reticle centered perfectly. Let us know if you have any questions.

About the author

Patrick Howard

I have been working as a gunsmith for 20 years. Rain, fog, moisture, high temperature, or even snow are all the things a product must withstand in order to be recommended by me.

Leave a Comment