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Why Does My Scope Lose Zero? — How to Troubleshoot & Fix It

Why Does My Scope Lose Zero

Holy buckeyes!

Sometimes, you just have those frustrating moments when you think you’ve got a perfect shot, only for it to miss.

I lost count of how many times that has happened to me, and I had to do something.

That is, until I realized that it was just a simple sighting problem! If this happens to you, it seems like your scoped rifle could have LOST zero.

What Does It Mean for My Scope to Lose Zero?

To zero in a scope means to align the scope with the bullet trajectory. This would allow the bullets to hit the target at a distance.

Of course, there are a lot of factors that go into making sure your bullet hits its target. There’s chamber pressure, wind speed, distance, etc.

While you can’t specifically dictate a bullet to go exactly where the scope is pointing, it is possible to adjust the scope so that the crosshair will point at the exact spot you want your bullets to go.

This adjustment, if done properly, is what it means to make a scope HOLD ZERO.

If you fire a shot, and the bullet is FAR off its aim, you could say that the scope has LOST zero.

How could this have happened?

Let’s look at some reasons for why your rifle scopes lose zero and how you can possibly troubleshoot it to ensure your scope will hold zero.

Why Does My Scope Lose Zero? — 7 Possible Causes

Now that we know what it means for a scope to not hold zero, let’s look at some of its possible causes.

1. Defective Scope

Man with defective scope

The simplest reason for a rifle scope losing zero could simply be that it is a defective or poorly-made scope. There can be many reasons for this.

  • Low-quality make and model
  • Degraded over time
  • Abuse of the rifle scope (dropping or bumping)

If you feel as though your rifle scope may be defective, it may be best to get a new, better-quality scope.

I couldn’t get one of my scopes to hold zero, and I thought it was just a sighting problem.

Turns out, it’s been damaged this whole time, and I unfortunately had to replace it.

Let this also serve as a reminder to regularly do scope maintenance!

If you feel your scope is NOT defective, but you still experience issues, you might want to revisit sighting into rifle scopes properly.

2. Barrel Heat

Scope barrel

This may be surprising, but the temperature of the barrel, especially for hunting rifles, actually plays a large role in the accuracy of the shot.

A barrel at AMBIENT temperature, also known as a cold barrel, makes the most accurate shots.

When a few bullets have already been shot, it is known as a hot barrel.

A hot barrel tends to shoot too high or too low.

The change in temperature as the barrel heats up causes it to swell and change in stresses to alter shots, causing it to shift a bit with every shot.

Additionally, a barrel can even fall off if it overheats!

This is especially an issue with rifles that have a thin barrel and a high volume cartridge.

THIN barrels tend to heat up FASTER, while high volume cartridges tend to shoot hotter.

While rifles with this configuration make for a first shot with a deadly aim on a cold barrel, the heat from this combination of factors is disastrous for any ensuing shots.

The combination of these two factors makes for a DISASTER.

I always let my barrel cool down after a few shots to prevent overheating, and you should as well!

3. Dirty Barrel

Man cleaning rifle

Dirty barrels are quite normal on the field as some debris is leftover from each bullet that leaves the rifle.

However, a dirty barrel can also affect the accuracy of your shots.

Rust and debris inside the barrel can cause BLOCKAGE and cause the shot to lose accuracy, even if the rifle scopes are accurate.

Additionally, any corrosion or copper fouling inside the barrel may also cause a misfire or a failure of shooting.

I forgot to clean my barrel after multiple days outside, and experienced inaccurate shots as a consequence.

With a dirty barrel, your shots may be missing even if you’re doing everything else right.

I always make it a point to clean my barrel after an outdoor session to have it ready for next time.

4. Wrong Ammunition

Loading ammo

Some bullets may have variations and inconsistencies that may cause your rifle to lose zero.

For example, in my case, I once had misshapen rounds, so they shot differently from my rifle.

Your rounds may also have an incompatible weight.

Some bullets may also be corroded or dirty, thus contributing to a change in direction and shot.

It is important to note, also, that different rifles are suited for different rounds.

Using the wrong type of bullet may damage the shot and the rifle if it is not made to sustain such heavy recoil.

5. Mounting Problems

Scope mounted

Faulty scope mounts or bad mounting can definitely contribute to the inaccuracy of rifle scopes.

When your scope mounts are not screwed properly, the scope rings may become loose with every shot, inevitably throwing off your rifle’s ability to shoot properly.

On the other side of the coin, there is the issue of the screws being tightened in far too much, which is what happened with me.

I thought that making the screws extra tight would keep everything in place, but it caused problems with the screw holes and mount base.

There can also be the issue of the scope not being mounted properly.

For instance, it could have been mounted upside down, with the windage turret on top and the elevation turret on the left side.

The scope mount could also have been attached slightly off-center on the gun due to operator error.

I don’t know about you, but I know I can’t read upside down, much less shoot.

6. Faulty Adjustments

Adjustment turret

The elevation and windage turrets on your scope may be improperly adjusted.

Elevation turrets control the movement of the reticle up or down, while the windage turrets control it from left to right.

If scopes aren’t adjusted properly, they may be pointing a bit too much to the left or right, or angled too low or high, for the right shot.

Even cheap scopes can last long if you adjust them properly!

7. Parallax Issues

Looking through scope

Scope parallax is an optical illusion wherein the reticle doesn’t point to the exact location of the target.

It may cause an object to appear slightly to the left or right of its actual position, making you lose your shot.

Parallax issues are most prominent in scopes with HIGHER magnification.

To avoid parallax issues, look for a scope that can make an auto adjustment to make up for it.

You also need some practice to understand how to make the necessary adjustment to your aim needed to make up for the parallax.

How to Troubleshoot Your Rifle Scope

Now that we know some possible causes for your hunting rifle to lose accuracy, let’s look at some possible quick fixes.

1. Allow Your Barrel to Cool Down Between Shots

As mentioned earlier, I always let my barrel cool down after a few rounds to prevent it from heating up.

Hot barrels tend to give inaccurate shots. As such, you’ll want to have as close to a cold barrel as you can for your shots.

If you can, wait a minute or so before firing again. Waiting will allow your gun to recover and shoot better shots.

2. Clean Your Rifle Regularly

You always want to be sure that the barrel of your rifle is clean of any rust, debris, or corrosion.

Make it a point to make regular checkups and clean your rifle regularly. Don’t walk into the field or range with a dirty barrel!

Once you are on the field, be sure to clean your barrel. 

I recommend cleaning the barrel with a powder and a copper solvent every 20-30 rounds. This will ensure a smooth shooting experience.

3. Buy the Right Type of Ammo for Your Rifle

Don’t just use any kind of bullet for your rifle. Be sure to check what TYPE of bullet your rifle is made for.

Remember that rifles are not created equal, and there is a large range of ammo to choose from.

Once you know what sort of bullets your gun can and can’t take, you can experiment with different brands.

Don’t be afraid to shoot different kinds of ammo until you see what kind of bullet and brand your rifle likes.

It’s best to check these at a shooting range and not out on the field so that you won’t be missing out on any hunting.

It’s also best to get bullets from the same lot to avoid inconsistencies.

4. Secure Your Mounting Properly

Be sure that all the screws in your scope mount, especially on the scope rings, are tightened properly; not too tight, not too loose.

If you are having problems with the accuracy of your shots, you may want to check on the screws of your scope mounts.

Fixing scope mount

Also, make sure that your scope is right side up to avoid any problems such as shifting the reticle left or right when you really meant to shift it up.

I make it a point to ALWAYS check on the security and condition of the scopes rings and scope before actually shooting my gun.

I suggest buying high-quality scope mounts to keep your rifle secure and wiggle-free.

5. Bore Sight Your Rifle

Boresighting helps zero the scope by aligning the barrel’s bore axis with the target.

While it can be done by a laser or mechanical bore-sighter, it is also possible just to eyeball it.

In my experience, eyeballing is a great way to fix your aim without any additional expenses, even if it sounds crude and difficult.


If you want to boresight your gun without any additional tools, put the gun in some sort of cradle that will stop it from moving.

A weighted cardboard box notched on the two top edges makes for a great DIY cradle.

Once you’ve secured your rifle, you can move on to adjust your rifle:

  1. Remove the bolt.
  2. Look down the barrel and manually adjust it so that a bull’s eye is centered at about 30 yards.
  3. Adjust the turrets until the reticle is centered to the bull’s eye. Be careful not to move the rifle!
  4. Take a shot at a paper from about 10 yards.
  5. Taking note of where the hole appears, realign your rifle using the windage and elevation dials so that the crosshair is right above the first shot.

Once you’ve followed these easy steps, the barrel and scope should now be aligned to point at the same place.

It should be good for 30-200 yards, or even 250 yards if you really did it well.

6. Be Aware of Proper Click Adjustment

It is especially important to know how your scope moves and how you can calibrate your scope accordingly.

Some scopes move at a 1/2 inch per click at 100 yards, while others scopes still move at 1/8 an inch per click. 

Most scopes move at 1/4 inch per click.

Let’s talk about proper click adjustment with regards to a 1/4 inch click since it is the most common out there.

If you want to shift your point-of-impact 1 inch at 100 yards, you’ll need to dial in four clicks.

Let’s say, then, that you fire your first shot and find that it is skewed 2 inches to the left. 

To remedy this, you’d have to dial in 8 clicks to the right.

However, if you fire and find that it is 4 inches too high, you’ll need to turn the elevation turret 16 clicks down.

Fixing scope turret

I know it’s a lot of trial and error and math, but it’s the only way to ensure your shots land where you want them to.

After your first shot, take note of where your next shot lands. If it didn’t shoot as expected, there’s no need to panic.

However, don’t rush to readjust your clicks!

The erector tube, which adjusts the reticle position, sometimes doesn’t shift as expected with the dials.

However, it does shift after being jarred by recoil.

To use this to your advantage, take two more shots to give the erector tube a chance to shift properly.

If it does move properly, with just that one shot out of place, then the erector tube was probably just stuck.

TAKE NOTE: If you moved to adjust your clicks immediately after the second shot before recoil can make any adjustment to the reticle, you might end up with a double adjustment, which will just make things worse for you.

7. Rap the Cap

“Rapping the cap” is a way to minimize the possibility of the erector tube getting stuck while zeroing in. It is also great for clearing up a sticky point.

It may sound a bit intimidating, but it’s actually quite simple. There are two ways to do it:

Method 1:

After turning the adjustment clicks, tap the top of the turret several times. This can be done with a screwdriver handle and is meant to mimic the recoil that loosens up a stuck screw/tube junction.

Method 2:

  1. Memorize the current turret setting and turn the dial to make a complete rotation past that number.
  2. Make another rotation around the setting.
  3. Return to the previous setting.

The point of the second method is to cause added pressure that can clear a sticky point.

For best results, combine the two methods for better chances of success.

Frequently Asked Questions

If zeroing your scope still sounds a bit complicated, here is some extra insight to make the process easier.

Do You Have to Zero Every Time?

Zeroing every single time isn’t a requirement, but it will help to practice doing it in case you land inaccurate shots.

In my opinion, if you take care of your reliable scope as if it were your own child, you won’t have to zero that much at all!

At What Distance Should I Zero My Scope?

A good distance to zero your rifle scope would be 100 yards, which is what I usually start with.

If you are a beginner, you can also start at 50 yards and work your up to farther distances, like 300 yards.

Do Cheap Scopes Hold Zero?

I would not trust a cheap rifle scope to hold zero as the poor quality will likely be the cause.

However, there are plenty of AFFORDABLE, cheaply-priced scopes that hold zero just fine!

I guess it depends on your definition of cheap. For me personally, I doubt a cheaply-built scope will hold zero very well.


Close up of scope

I’ve given above a few reasons for your rifle scope to possibly lose zero, as well as how you can fix this problem.

I hope my little tips and tricks helped you diagnose and troubleshoot any problems you have, not just with your hunting rifle but with any of your guns!

However, if you’ve tried these and all else fails, it may be time to retire your poor-quality scope and find yourself another budget scope that can give you the love you deserve.

You can also practice with iron sights to improve your aim.

Keep shooting and practicing! Good luck!

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