How to Mount Scope on AR 15 with Front Sight

How to Mount Scope on AR 15 with Front Sight?

One of the widely used rifles today is the AR15. It has an accurate, durable, and sturdy fixed front sight. Some shooters would want to add a secondary scope on Ar15 to help them improve their shooting skills. This is common among shooters who shoot long range or more than 100 yards.

It may require an expert to do the mounting of the scope. But, we have made the process easier for you in this guide. Below are the steps on how to mount a scope on AR 15 with a front sight.

What You Need


Before you proceed with the process, you need to prepare the tools you need to complete the mounting.

  • Alcohol – is used when cleaning the screws and the rail
  • Gun vise or rest – you will need this to hold the rifle in place while mounting the scope and testing the newly installed scope.
  • Torque wrench – used in tightening the screws
  • Bubble level – you will need it in leveling
  • Scope mount – some scope comes with a mount. If not, you can purchase it separately
  • Hex bit tool – is a very handy tool used when working in any firearm

Steps on How to Mount Scope on AR 15 with Front Sight


It is possible to mount a scope on AR 15 with front sight. When using low magnification scope, you will see the sight through the scope. But on higher magnifications, you will not see the sight. For some shooters, this can cause problems, but for others, they do not have any issue with it.

To avoid such a situation, you can get a AR 15 with a foldable or adjustable front sight. Some rifle owners would cut the front sight, which we are not recommending. Let’s proceed with the steps on installing the scope.

Step #1 Preparing the Rifle

When working with a rifle, safety is essential. Make sure your AR 15 is empty and unloaded. Remove the magazine and clean the screws and rail with alcohol. Then set your gun on the gun or vise rest and make sure it is well secured. Before you start, do not forget to level your weapon using a bubble level. Check if all the tools you need are complete.

Step #2 Add the Scope Mount

The next step is placing the scope mount. As mentioned earlier, some scopes come along with mount, but if the one you bought does not include it, you can buy a scope mount for your AR-15 separately. Position the mount above the upper receiver. Avoid placing it on the free-floating rail and the upper receiver as it could cause stress on the gun’s tube.

Tighten the scope mount by hand first to make sure it is stable but not too tight. Then complete the tightening using the torque wrench. Check the scope mount instructions included in the package. You should strictly follow the torque level indicated in the manual so you will not over-tighten the mount.

Step #3 Add the Scope

If you are sure your mount is secured, you can now add your scope. Position the scope on top of the mount. The rings should be placed on the scope’s flat surface. Take the top part of the scope rings, position them on top of the scope, and start securing it. Follow the X pattern in tightening the scope rings. Make sure not to tighten the scope rings yet completely.

The X pattern is used to ensure each side will have the same gap level as you tighten it. After you tighten the scope rings and there is still a gap remaining, check the scope’s eye relief and find the perfect position. 

Step #4 Leveling

In leveling, you need your bubble level. Position the bubble level on a flat part of the tube. It will help if you have a gun rest. Ensure your AR 15 is level completely. Then, level your scope. You need to ensure that your reticle is aligned vertically and horizontally before leveling the scope.

Align the reticle to a target or door frame, vertically verified by a bubble level. Once you have correctly aligned the reticle, position the bubble level on top of the scope and ensure it is aligned. To make sure it is properly aligned, you can shoot and test the scope and adjust accordingly if needed. 

Step #5 Completion of the Mounting

Finish up the tightening of your scope rings. Keep in mind not to tighten one side first and then the other side. Use the X pattern to make sure you have tightened the side evenly. Doing this will get rid of the space on each side while you do the tightening of the scope rings. Now that you have completed the mounting of the scope on your AR 15 with front sight and you are sure the scope is secured, you can now bore sight your rifle.

If you want to use your gun for 600 yards targets or higher, you have to lap the rings. This is done by sanding down the inner part of the rings to ensure the best possible surface-to-surface contact.

Frequently Asked Questions (FAQ)


Where to mount scope on AR 15?

Mount the scope above the upper receiver. You should not place it on the free-floating rail and the upper receiver since it might cause stress on the rifle’s tube.

How high should a scope be mounted on an AR 15?

The general rule in mounting the scope is to mount it as low as possible, without any part of the scope touching the barrel or any part of the gun.

Does scope mount height matter?

Yes it does. The lower you mounted the scope and the closer it is to the axis of the bore of your gun, it will provide a consistent sight image needed for accurate long-range shooting.

Final Thoughts


The key to a successful mounting of your scope on AR 15 is to make sure the scope and the scope mount are compatible with your rifle. Also, the scope should be properly leveled. Be patient in leveling the scope. This will have a significant, positive effect on your accuracy.

If in case you have difficulties in leveling and adjusting the scope, you can seek professional help. This how to mount scope on AR 15 with front sight guide can make things easier for you. Actually, you can complete the process all by yourself. The process is not as complicated as some of you might think. But you need a lot of time, proper tools, and patient to complete the job. If you have questions or want to share your thoughts about the topic, feel free to comment below.

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