How To Mount A Scope On A Rifle Without A Rail (Shooters Guide)

Mounting a rifle scope is extremely difficult and requires hair-thin accuracy and soldier-like discipline. Numerous things can go wrong, possibly ruining your beloved rifle. This complete guide will help you mount your scope on a rifle. However, individual rifles are incredibly variable, thus, seeking a professional’s guidance is still advised before you proceed. 

Directions: How To Mount A Scope On A Rifle Without A Rail

mounting a scope to a rifle

Step #1 – Find A Gunsmith

Let’s say you just bought your favorite 300 Win Mag scope, it’s time to install it. If your rifle doesn’t even have a rail, that means using a pair of quick disconnect scope mounts isn’t going to cut it.

First things first, you will need to locate a gunsmith. Using a gunsmith to drill, adjust and mount a scope for you is the easiest but the most expensive option. However, it is the best option if you have a good gunsmith who knows what they are doing and you do not have the time to mount it.

Before visiting the gunsmith, you must acquire the specific ring screws, rings, and rails. If the quote is not to your liking or you want to do it yourself, you can continue with step #2

Step #2 – Time To Drill & Tap

After acquiring all the tools needed for mounting a scope on a rifle, you will need to begin by drilling some holes. Here is the step process:

  1. Secure your receiver in a sturdy gun vise that will not damage it.
  2. Use a specialized jig with pre-drilled holes properly aligned to have that added precision.
  3. Place the jig on top of your rifle. Please note that you must drill holes into the gun’s receiver if you have an older rifle. The modern-era rifle is great in this regard, as they already have pre-drilled screw holes, so feel free to skip ahead.
  4. Before drilling, seek expert advice from a gunsmith, as each rifle has unique drilling parameters.
  5. Now, incorporating the advice from the expert gunsmith, use your drill machine with high-quality carbon drill bits and, guided by the jig already placed on top of your rifle, drill your holes into the gun’s receiver.
  6. Next, use the thread taps to create a thread in the holes for the screws. Take care not to drill too deep. Use calipers to take exact measurements to check in this regard.

Step #3 – Install Your Base Plate

If you check our guide for installing a scope on your AR-15, you won’t find directions for base plate installation. But that’s because most rifles come with a base plate and rail already installed. You will need to install the base plate onto your rifle. It is advised to use Loctite before you screw down your base plate onto the receiver. This will help prevent moisture from interfering with your mount and provide a more permanent union.

Aligning your base plate with the screw holes, you can now screw down the screws into the receiver.

Step #4 – Mount Your Rail

You must pay close attention when mounting your rail. Make sure the rail type can accommodate the specific scope you want to mount on your rifle, a Picatinny rail is the rail of choice for most gunsmiths and it fits popular optics like the Ozark Armament Razorback.

You can also apply blue Loctite to the rail before installing it onto the rifle to ensure it is well secured.

Step #5 – Mount Your Rings & Scope

Now it is time to mount your scope rings and also mount your new scope, done simultaneously. Double check that the ring screws and everything else are tightly fastened. Mounting quality scope rings is a critical part of learning how to fix a canted reticle.

Ensure the scope is mounted correctly to prevent the objective bell from contacting the gun barrel. Also, check that adequate clearance is available to keep the scope tube or bottom half of the scope rings from interfering with the smooth bolt cycling.

Step #6 – Laser Bore Sighting

After successfully installing the mounting system, it is time to bore sight your new scope and rifle combination. Ensuring the installation process went flawlessly.

Using the best bore sighter is recommended for sighting your rifle as the visual accuracy of your rifle scope sights will be markedly improved. You can also use a laser bore sight to reset your scope to factory zero in a few minutes.

How to bore sight your rifle – a quick guide:

  1. Insert the bore sight into the muzzle end of the barrel or place it into the gun’s chamber, depending on your specific laser bore sight. The laser will shine through the barrel in the aimed direction.
  2. Set a target at 25 yards
  3. Look through the scope at the target, you will notice the laser point and reticle on the target.
  4. Make the necessary windage adjustment and elevation adjustment until the reticle is aligned with the laser point.
  5. If you need to adjust the reticle more than 6-8 inches, double check that the scope is properly mounted onto the gun and the rings are properly fastened.

After the rifle has been bore sighted, it is advised to take it to a shooting range. Take solid rest and shoot a couple of rounds to ensure that your rifle scope has been properly mounted and perfectly level. You can also make the necessary windage and elevation adjustments for your rifle. These tips also hold true when sighting a night vision scope as well!

Equipment You’ll Need

You will need to have the right tools to help you mount your rifle scope successfully on a rifle without a rail:

Type of Rifle

As already mentioned, the date your rifle was manufactured will determine whether you need to drill holes for your base plate. Modern rifles have pre-drilled holes, while older rifles, unfortunately, don’t.

Another thing to take note of when deciding if you want to mount a scope is the fact that the ergonomics of some iron sight rifles will not work with a scope mounted. Causing all types of inconveniences, such as:

  • Difficulty in getting adequate eye relief.
  • Struggle to achieve the correct field of view (FOV) for your reticle, making it difficult to see your target.
  • Having trouble getting into the correct shooting position.

Correct Scopes

You don’t need a scope to mount a rail to your gun. However, the added accuracy of having a scope at hand for constant checking during the mounting process is advised. It acts as a reference guide to help you adjust your scope mounts.

The scope should fit your rifle accordingly. If the scope on a rifle is too big for the rifle, you can have problems getting into the correct shooting position or difficulty obtaining eye relief from your scope.

Correct Rings and Rails

Things to take note of when purchasing mounting systems:

  • Size – The rings and rail should be the same size as your rifle and scope to prevent the bottom half of the two scope rings or scope tube from interfering with the bolt cycling of the gun. Many scopes I use run 30 mm scope rings for installation.
  • Quality – The mounts should be of the highest quality. Low-quality mounting systems often degrade after a few years, leaving a loose adjustment.
  • Screws – Are screws included in the package? Are these the correct screws, and do the screws match the overall color of the mounting system?

Almost all gun shops offer rings and rails, yet ask the gun shop employee what rings and rails will work best with your scope and particular rifle. If any of these parts are broken there is no way you’ll be able to level your scope properly.

General Tools

Here is a list of some of the general tools you will need. Even if you purchase one of my 350 legend scope recommendations, you may still need these. Please note that even though they are listed under general tools, it doesn’t make them less important for mounting a rifle scope.

  • Drill – You will need a drill with a recommended torque of at least 500 in-lbs. Remember, the torque specs decrease as the drill’s speed increases because they are inversely correlated. A bench drill is the best option, as drilling into the receiver’s steel is not easy.
  • Drill Bits – You will need to use high-quality carbon drill bits to alleviate pressure off of the drill itself.
  • Thread Tap – The thread tap should be of the best quality, it will be used to create a thread in ultra-hard steel. Using a poor-quality thread tap on this job can lead to the thread being damaged, creating a thread that won’t work with the screws. Also, get the right size that matches the screws’ size.
  • Loctite – Used on the scope bases to remove moisture and allow for sturdy scope mounting.
  • Jig – The rifle jig is essential for knowing where precisely to drill as described by the gun’s manufacturers.
  • Laser Bore Sight – Will be used to align the bore barrel of the gun with the mounted scope.
  • Allen Wrench – Will be needed to tighten the rings of the scope on a rifle, or you can use a torque wrench which will measure the torque poundage when tightening the screws (the recommended is 15-18 inches per pound)

Types of Rails and Scope Rings

There are several types of rails and scope rings for rifle scopes, however, the most loved by gunsmiths are:

  • Picatinny Rail and Ring Type- The most popular rail and mounting for a rifle scope. It has a universal measurement making it easier for manufacturers to produce accessories to fit onto the mount. Slots extend down the rail allowing the mounting of the scope forward.
  • Weaver Rail and Ring Type- Predates the Picattiny and has ununiform slot distances between rails. The ring size will need to match the tube widths. Rings are first secured around the scope and then onto the rail. It has a low-profile mounting, so the lower half of the tube can become a problem with bolt cycling.
  • Dovetail Rail and Ring Type – Less often used than the Picatinny and Weaver, although popular on rimfire and air rifles. The ring size should match the tube size, and the ring base should match the size of the dovetail rail.

What Can Go Wrong?

If the scope is not mounted properly, then the accuracy of the rifle will be compromised. This also holds true for a traditional bb rifle scope. Regardless of what scopes you are using to mount on your guns, the technique must be correct. Mounts should be steady and match the type of rifle.

Also, mounting at the incorrect height can cause improper eye relief when looking through the scope. Or you cannot complete a bolt cycling as the scope interferes with the cycling sequence.

Do not use Loctite with vortex optics, as they can act as a lubricant, creating additional torque that might exceed the recommended specifications. This can cause damage to your rifle scope.

Overtightening the base and ring screws can cause damage to the scope and will affect the performance of that scope. Best to follow the recommendations as instructed by the manufacturer and only adjust if need be.

Frequently Asked Questions

Can I mount scope without vise?

Yes, you can although not advised. A vise is used to hold the gun steady and, if not present, might lead to the gun falling when you have started mounting. The alternative is to use a sturdy cardboard box cut at both ends into a V-shape for the gun to rest.

How does a cantilever scope mount work?

It is a one-piece mount adapted to be attached to a Weaver-style Picatinny rail. Rings are connected to the base, with one of the rings extending past the receiver over the barrel.

Can I mount a rifle scope myself?

Yes, but I recommend reading this article first, as there are numerous factors you should consider.

What are the different types of scope mounting rails?

The most popular scope mountings available for your rifle are: Picatinny Mounting, Weaver Mounting, Dovetail Mounting

The Bottom Line

It is crucial to follow the steps diligently to prevent possibly damaging your rifle or scope. You should only use materials of high-quality, fit for your esteemed rifle.

In the end, although it is better to let a gunsmith mount your rifle scope, it is possible to do it yourself. Seek professional advice before starting to provide you with guidance on your specific rifle model.

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.

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