By Scott Haugen     Published on July 14, 2023

Mounting a rifle scope is a simple process. One of the benefits of mounting your scope on your rifle is it allows you to achieve a personalized fit. In addition, the process will familiarize you with how the scope and rifle work together to optimize performance and accuracy.

Before mounting a rifle scope, you'll need specialized tools to complete the process efficiently. A gun vice like the Real Avid Master Gun Workstation or the Best Gun Vise from Tripton will stabilize the rifle. These platforms also allow precise positioning and alignments. 

A torque wrench, like a Wheeler F.A.T Wrench, is highly recommended over hand wrenches. Hand wrenches are small and difficult to handle and often result in over-tightening and stripping small screws. 

Depending on the rings you use to mount your scope, you may need a large or small screwdriver or a small crescent wrench. A leveling system is also a must-have. 

Before setting the rifle in the gun vice, make sure that it is completely unloaded. Then, double and triple-check to ensure the firearm has no rounds in the chamber or magazine. It’s also a good idea to remove the magazine if the firearm has one. If mounting the scope on a bolt-action rifle, remove the bolt from the unloaded firearm. (Once the bases are installed, you’ll want to check inside the receiver to verify that the base mounting screws are not making contact with the bolt.)

With the rifle secure in the gun vice, use a small screwdriver to remove the plug screws from the rifle’s receiver. Most rifles are drilled and tapped for a scope. Next, mount the bases onto your rifle. Bases come in one or two pieces; which one you use depends on your rifle and the scope you’ll be mounting. Two-piece bases fit the front and rear mounting locations on the rifle’s receiver. The screws match each base, so do not mix them up. Using a screw that is too long can affect bolt operation and using a screw that is too short can easily strip in the receiver.

Get the screws started and lightly seat them in the bases. Be aware that rifles like the Browning X-Bolt and X-Bolt 2, with the X-Lock mounting system, require that the scope base screws be tightened in a cross pattern to apply even torque to the base. Next, set the torque wrench to the manufacturer’s recommended specifications and install the bases. Torque for most rifles is usually between 25-30 inch-lb, but some rifles like the X-Bolt have a lower specification of 18 inch-lb. These differences are why it’s always a good idea to reference the firearm owner’s manual, and the instructions from the accessory manufacturer, when adding a scope or accessories to ensure you are installing them correctly. Do not apply too much pressure and over tighten the base screws, doing so can strip or break the base screws and possibly damage the threads in the receiver. Correct torque is also critical to keeping the scope secure under recoil.

Install the bolt and carefully work it with the bases securely installed to ensure it operates freely and isn’t making contact with the base screws. Don’t skip this step. If there is bolt interference, now is the time to fix it. Again, if the base screws are too long, they will interfere with the operation of the bolt and can damage it.

Set the rings into the bases and lightly secure them. Selecting rings that match the scope’s diameter and the rail or bases is essential. Most scope rings come with a top (cap) and bottom (base) part. Remove the ring caps and set your scope into the ring base. You must secure the ring base(s) to the scope base(s). 

Gently slide the scope back and forth to ensure the rings are correctly aligned. The scope should glide with very little resistance. The rings should contact only the scope’s main tube and not any angled edges. If the rings are contacting an angled edge on the scope, move the position of the rings. Make sure the front of the scope clears the barrel. If mounting a rifle scope with a large objective lens, you may need higher rings to mount your scope so the front of it clears the rifle barrel.

With the rifle scope nestled into the bottom portion of the rings, install the ring caps on the ring bases using the screws supplied. Snug the screws just enough to lightly hold the scope. 

Alternately, using an integrated scope mount simplifies the mounting process by combining the scope ring and base into a single, precision-machined unit that is both lightweight and extremely strong.

Now it’s time to find the proper eye relief or how far the scope should be from your eye. If the scope has variable magnification, set it to the highest power. Remove the rifle from the vice and shoulder the gun while looking through the scope. You can move the scope forward and backward to find exact eye relief because you have yet to lock down the rings.

With your cheek comfortably positioned on the stock, move the scope until you see daylight in the entire scope. Do not move your head back and forth to fit the scope; move the scope to accommodate you. There should be no shadows around the edges of the scope. This is called a full-sight picture. Move the scope back and forth until you achieve a full sight picture. You can also rotate the scope to get the reticle level before finalizing this process with a leveling system. 

Once you feel you've achieved the proper eye relief, gently and slightly lower the rifle about six inches, close your eyes, then shoulder the rifle again. With your head in a comfortable position on the gunstock, open your shooting eye to see if you still have a full-sight picture. If you do, you have the perfect eye relief. If you don’t, do not move your head, but adjust the distance of the scope until you see a full-sight picture. Repeat this process as needed.

With the scope in position and your eye relief determined, place the rifle back in the gun vice and, using your torque wrench, secure the rings to the scope bases following the manufacturer’s instructions. Slightly tighten one ring and then the other, incrementally tightening the front and then the rear to ensure an even seating of the rings to the bases.

Next, affix a level to the rifle. Wheeler's Professional Reticle Leveling System works well to secure a level to the rifle barrel. If you’re using a Picatinny rail scope base, you can get a rifle level that fits onto the Picatinny rail. Move the rifle side to side in the gun vice until it’s level and secure it in position. With the rifle level, place the second level on the top turret of your rifle scope. You may need to remove the turret cap to get a flat surface to set the level on. Slightly rotate the scope side to side until the scope is level with the rifle. With both the scope and rifle level, it's time to tighten the scope ring caps.

Set your torque wrench to the manufacturer’s specifications (generally 15 to 18 inch-lb) and secure the top of the scope ring caps to the scope ring bases, which are already secured. Incrementally tighten the scope ring caps in a criss-cross, or diagonal, pattern. This will ensure even pressure on each ring. Be sure the gaps between the ring caps and ring bases are equal on both sides of the scope. During the tightening process, ensure the bubble on the scope stays level. With the scope secured, double-check the rifle and scope levels. You're ready to bore-sight your rifle, then head to the range to start slinging lead. 

Should any screws for the bases or rings be covered in oil, you will need to degrease them before installing so they will securely hold. Also, while it's not necessary, you can apply a medium-strength threadlocker like Loctite 242 to secure the screws. This is more commonly used on magnum-caliber rifles or with heavy scopes.

Be sure not to over-tighten any ring screws, as this can damage the scope and compromise shot accuracy. Likewise, be sure not to under-tighten the rings or bases, as this will allow the scope to move and have a different point of impact each time you fire the rifle. A torque wrench will alleviate either of these problems. Some scopes also come with the manufacturer's suggestion for torque settings.

The price of a rifle scope depends on many things like glass quality, overall build, magnification range, etc. While you can get into a lower-end 3x9 scope for around $120, most mid-range scopes are going to cost between $300 and $800. Top-end scopes with custom turret systems and larger scale magnification ranges typically run between $1,500 and $2,500.

Many top-end scope makers allow you to enter your rifle make and scope model into an algorithm on their website. Then, the system will generate a scope mounting system. Another route, especially if you plan to select scope rings and bases that aren’t made by the scope maker, is to know the tube size of your scope (1 inch, 30mm, or 34mm), your ring-height choice (high, low, medium, and standard), and the base mount the rifle requires. If you have this information, you can get rings and bases to mount your scope from most any ring/base maker. Most rifle user manuals provide base and ring information.

Mounting your own rifle scope may sound like a tedious chore, but it’s not. In fact, it’s no more of a task than cleaning your rifle from top to bottom. If you have the right tools and don’t get in a rush, mounting a scope takes little time, and if you do it yourself, you know beyond any shadow of a doubt that the task was completed correctly and that your scope is set right for you.