How To Mount Scope On Ar 15 With Front Sight? A Simple Guide

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Are you wondering: ‘How to mount the scope on ar 15 with front sight?’

The Ar15 is a very popular and high-quality rifle, but you may struggle with using its fixed front sight scope. Upgrading the regular stock scope on the front sight of the Ar 15 can increase your shooting skill significantly.

Based on the step-by-step guide provided in this post, you can learn to mount the scope on the Ar15 effortlessly. Continue reading, and I will show you!

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How To Mount Scope On Ar 15 With Front Sight? 

You can install the scope on the Ar 15 with front sight, as the component does not hinder the physical installation. Yet, the process is quite complicated.

You will be able to see the sight via the scope with low magnification. However, you cannot see the view on scopes with higher magnifications. Follow these steps carefully, and you can mount the scope on Ar15 with minimal effort.

The process is much simpler if your rifle has a front sight that can be flipped up.

Without co-witnessing with the iron sights, you just need to flip down the front sight and mount the scope.

The process is more complicated for the fixed front sights (FPS). This type of front sight may hinder the scope’s view with lower magnifications.

Without co-witnessing the red dot with the iron sights, you will encounter some difficulty and distractions when aiming and shooting.

How To Mount Scope On Ar 15 With Front Sight

Gather The Needed Material 

Here are the required tools to install the scope on Ar 15 rifle with a front sight.

  • A torch wrench
  • A hex bit tool
  • Rubbing alcohol
  • Cleaning patches
  • A separated mount (optional)
  • Gun vise (optional)
  • A bubble level

You need the torch wrench to install the firearm easier, while the rubbing alcohol helps you clean the gun and the screws. For the scopes that don’t have an integrated mount, you can buy a separate mount.

You can hold the gun by hand, but a gun vise will help you save a lot of effort. Finally, the bubble level enables you to level the scope properly without ruining its accuracy.

Absolute Or ⅓ Co-Witness

Absolute means that the front irons, the rear, and the red dot are perfectly aligned when you flip up the irons. Another option is ⅓ co-witness, which means that the rear and front are aligned with the lower ⅓ view of the red dot.

Your Ar 15 rifle has a red dot that is designed to work with both ⅓ and absolute co-witness. The absolute co-witness is the best choice when you have flipped-up irons. If you don’t have the flipped-up iron, go for the ⅓ co-witness.

Unload The AR-15 Rifle

It is very dangerous to handle a loaded weapon. The first and most important thing is to unload your Ar-15 rifle.

It ensures your safety when you accidentally press the trigger. Remove the magazine first and check if there are any bullets left in the chamber.

You can apply the alcohol to the cleaning patches and clean the dirt or excess oil in the rifle’s components. Before mounting the scope, you need to remove the front and rear sights of the gun.

Removing the rear sight is very simple, but be careful with the potential gas block inside the front sight. Remove the screw and get it out of the flat upper receiver to remove the rear sight.

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Place The Rifle

Set your Ar 15 rifle on the gun vise after unloading and cleaning. It will help you secure the position and install the scope easier. The tool also helps you test the precision of the scope after installation.

Use the bubble level to place your gun in a position aligned vertically with the scope. These steps increase the accuracy of the weapon.

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Attach The Scope Mount 

The steps are quite different based on the type of scope mount equipped on your scope. For the scopes with a red dot, they have a built-in optic and scope mount that can be attached to the rail quickly.

Don’t place the mount on the upper receiver, or it may cause unwanted stress on the rifle’s tube. You can use the torch wrench to adjust the screws to suitable torque levels.

Then you need to tighten and stabilize the mount at that torque level. The hex bit tool can help you avoid over-tightening the scope and external damage.

Place the Scope on the Scope Mount

The next step is to place the scope on the mount after attaching the mount to the rifle. For the red dot, you can skip this step as the scope is already attached with the mounting.

If you use a separated mounting, you can attach the scope based on the provided instructions. Each mounting works differently, but you need to place the rings on flat surfaces. Also, don’t put the scope close to the barrel.

The gap between the two rings should be equal so that you can adjust the optic with ease. The last step is to adjust the eye relief to your desired position.

Level the Scope

You can use the bubble level to level the scope when everything is set in place.

First, adjust and align the reticle using a verified target (the door jamb, for example).

Then, place the bubble level to align the crosshair on the scope. When the optic is aligned, you can aim and shoot with more accuracy.

Lap the Rings

Lapping the rings can give more precise contact between the optics and the rings, but it may damage the ring. You should find a gunsmith who has a deep understanding of the gun’s structure to do this step.

For more in-depth instructions, consider watching the video below.


The bubble level is essential for mounting the scope on the Ar-15 rifle, so you should prepare one before installing the scope. Avoid over-tightening the sight as it may cause damage to the gun.

The optics may not be accurate after installation, so you need to adjust them accordingly. It is best to mount the scope on the free-floating rail to get higher magnifications.

Higher scope magnifications mean that the front sight is not obstructed and hinders your view, enabling you to shoot more accurately.

The low magnifications from 2x-4x may cause front view obstruction. So, higher magnifications (9x+) are recommended to get rid of the annoying obstruction.

How To Choose The Suitable Scope For Your Ar 15?

The first thing to consider when choosing a scope is its magnification level. A 9X magnification means that the target is nine times larger when looking via the scope.

You should choose higher magnification levels (8X at least) to get a clear view and shoot with more accuracy. Also, the larger the scope’s diameter, the better.

Larger diameters allow more light to get in and give a clearer view.

Although they will make your gun heavier, you will quickly get used to the weight. Meanwhile, you should choose smaller scopes for long-range shots.

Lastly, a fully and multi-coated scope is the best option. It has many layers of coats on the surface that decrease the glare and give you clearer aiming views.

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Understand the Types of Ar-15 Sights 

The AR-15 is a popular gun platform, and like any firearm, it needs good sights to ensure accuracy. There are many different types of AR-15 sights on the market, each designed to provide a different experience or meet certain needs. Here’s a look at some of the most common types of AR-15 sighting systems:

• Iron Sights: These are usually the standard sights that come with all factory AR-15s. The front sight is typically adjustable while the rear sight may be fixed or adjustable. They’re easy to use and dependable under normal conditions but can struggle in low light environments.

• Red Dot Sights: These are great for fast target acquisition and tracking. Red dot sights often require special rails or mounts to be mounted on the gun, but they are lightweight and very easy to use.

• Holographic Sights: These sights offer a lot of features that make them ideal for long range shooting. They usually have an illuminated reticle with adjustable brightness settings and can track a target even in low light conditions.

• Scope Systems: If you’re looking for precision accuracy at longer distances, then you need a scope system. These come in many different styles and sizes, allowing you to choose what is best suited for your particular situation.

No matter which type of AR-15 sight you choose, make sure it fits your needs and feels comfortable when used in conjunction with your rifle. With the right sight and practice, you’ll be able to hit whatever target you’re aiming for.

How to Properly Remove and Install Your Scope ?

Before you can use your chosen AR-15 sight, you’ll need to learn how to properly remove and install the scope. This is an important step in making sure that your rifle is properly sighted in for accuracy.

To begin, make sure that your gun is unloaded and the safety is engaged. Next, if you have a scope mount on your rifle already, then use a screwdriver to carefully remove the screws holding it in place. Once all of the screws are removed, slowly slide the mounting rings off of the rail so that they won’t damage the finish of your gun.

If you don’t have a scope mount already installed, then use a wrench or Allen key to loosen and remove the existing scope mounting screws. Once they have been removed, slide the new scope rings onto the rail and tighten them firmly with a wrench or Allen key.

Now you’re all set to install your AR-15 sight. Carefully align the mounting rings on the scope with those already mounted on your gun. Make sure that everything is lined up properly before tightening down each screw with a screwdriver or wrench.

Once your scope is securely attached to your rifle, it’s time to make any necessary adjustments for proper sighting in. All scopes will come with instructions regarding how to do this correctly, so make sure you read through these carefully before proceeding. When you’re finished making any adjustments, you’re ready to go out and start shooting with your new AR-15 sight.

Now that you have the basics of how to remove and install an AR-15 scope, it is time to go out and practice what you’ve learned. With a little patience and practice, you will be able to quickly become proficient in using your new sighting system.

Identify Best Placement for Your Mounted Scope 

Once you’ve installed your AR-15 sight, the next step is to identify the best placement for it on your rifle. Many people go for high-mounted scopes because they allow for better visibility and faster acquisition of targets. However, this isn’t always the best choice for all gun owners.

For example, if you plan on using your AR-15 in close quarters combat situations, then a lower mounted scope might be more appropriate. This will make it easier to move around corners and other obstacles while keeping an eye on your target. It also helps reduce fatigue by not having to look up so much when engaging targets at closer distances.

When looking for the best placement of your scope, make sure that you take into account how you plan on using your rifle. This will help you identify the most comfortable and effective spot for mounted scope placement. By doing this, you can ensure that you’ll be able to quickly engage targets without having to strain your neck or body too much.

With the right AR-15 sight in place and a good understanding of how to properly install it, you’re ready to start shooting with improved accuracy. Whether you’re an experienced rifle shooter or just getting started, these tips should help improve your chances of hitting whatever target is in front of you.

How to Ensure Proper Sight Alignment Once Mounted 

Now that you have your AR-15 scope mounted and in the right position, it’s important to make sure that it’s properly aligned. This is done by looking through the scope and making sure that everything looks correct from left to right and top to bottom.

If there appears to be any discrepancy in the alignment, then you may need to adjust the screws on either side of the scope. Be careful not to over-tighten them as this can cause damage to both your rifle and your scope. Once everything looks good from inside the scope, then you should be ready for sighting in.

Sighting in a rifle with an AR-15 sight is fairly straightforward but does require some time and patience. You’ll want to make sure that you use a good quality target and that your shooting distance is at least 25 meters or more. This will help ensure that the bullets are being fired with adequate accuracy for hitting your intended target.

Benefits of Mounting a Scope on an AR-15

By now, you should have a good understanding of how to mount an AR-15 sight and how to properly align it for optimal accuracy and precision. Mounting a scope on your rifle can provide many benefits, including improved accuracy when firing at longer ranges or in low light conditions. It can also make aiming much easier due to the use of crosshairs or other reticles that help you quickly acquire targets.

For those who are new to using AR-15s, mounting a scope is one of the best ways to increase your shooting performance. With some practice and patience, you can become proficient in sighting in and engaging targets with confidence and precision. Remember that proper installation and alignment are key when installing a scope on an AR-15, and that you should always practice proper gun safety when handling firearms. With a bit of dedication, you’ll be able to build the skills necessary for improved accuracy and precision.

Accessory Options That Enhance AR-15 Performance and Functionality

Along with a scope, there are many other accessories available that can enhance your AR-15’s performance and functionality. Things like extended magazines, bipods, tactical lights, and lasers can all be added to help you improve your accuracy when shooting. There are also plenty of grips and stocks available to help you find the perfect fit for you and your rifle.

No matter what type of shooting you plan on doing with your AR-15, having the right accessories in place can significantly increase its performance. From improved accuracy to enhanced speed when engaging targets, these accessories can help make sure that no matter what situation you find yourself in, you’ll always have the edge needed to succeed.

Final Thoughts

Choose suitable scopes based on your preferred shooting range and the weight of the Ar 15 rifle. Mounting the scopes is a piece of cake if you have the required tools and follow the steps correctly.

I hope that the instructions provided in this post can help you mount the scope on Ar-15 successfully. Thank you for reading!

Last Updated on October 28, 2023 by

2 thoughts on “How To Mount Scope On Ar 15 With Front Sight? A Simple Guide”

    • On an AR-15, the front sight is typically mounted on the gas block or the handguard. The location of the front sight depends on the specific configuration of your AR-15 and the type of front sight you are using. Here are the two common mounting options:

      1. Fixed Front Sight on Gas Block: Some AR-15s come with a fixed front sight post that is directly mounted on the gas block, which is located at the front of the rifle, directly above the barrel. This type of front sight is typically found on traditional AR-15s.

      2. Folding Front Sight on Handguard: Many modern AR-15s have a free-floating handguard, which means it does not touch the barrel and is mounted to the upper receiver only. On these rifles, a folding front sight is often attached to the handguard. The folding sight can be flipped up when needed for aiming and folded down when not in use, allowing the use of optics without interference.

      It's important to note that if you have an optic like a red dot sight or a scope mounted on your AR-15, it may not co-witness with the fixed front sight. However, some folding front sights are designed to co-witness with certain optics, providing an additional aiming option in case the optic becomes inoperable.

      The exact method of mounting the front sight may vary depending on the manufacturer and the specific model of your AR-15. Always refer to the manufacturer's instructions or seek assistance from a qualified gunsmith if you are unsure about the proper installation of any firearm components. Additionally, be sure to follow all safety guidelines and applicable laws when working with firearms and firearm accessories.


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