How to Properly Mount a Rifle Scope

Whether you’re a first time riflescope owner or a seasoned professional shooter, mounting optics can be a daunting task. Due to this, when they get a new scope, many people choose to get a professional gun smith to do the scope mounting for them. If you fancy having a go at mounting your new rifle scope yourself, then our detailed guide will be a useful tool to ensure that your newly mounted scope is safe, accurate and secure.

Before starting the process of mounting a riflescope it’s important to ensure that you have purchased the correct rifle mounts for your specific rifle and riflescope. There’s two main ways that you can connect a scope to a rifle.

Rail and rings

When they come out of the factory, most rifles have screw holes drilled in to the barrel so that you can attach a Picatinny or weaver scope base rail and then add your rings. Sometimes, this Picatinny rail will have been added to the rifle in the gun shop you purchased it from, other times you may opt to add one yourself. This set up is often favoured by target shooters who want the most accurate scope set up available but don’t mind about having a little extra weight that can be caused by the rail.

Scope ring with base

Many rifles have grooves cut directly in to them that allow you to fit rings directly into the barrel without the need of a rail. This allows you to save on weight. The rings that work with this set up are called Dovetail rings and they come in two standard sizes; 3/8 inch or 11mm, or in a specific size that fits only a few specific brands of rifle. When purchasing dovetail rings it’s important that you know exactly which model you need for your rifle to ensure that the rings fit and maintain a strong and reliable connection.

This information is usually available in the documentation that you receive with your rifle, or you can often find information about what scope mounts will be suitable for that rifle online or in the shop where you purchased it. If in doubt, you can contact us directly with the model of your rifle and we’ll usually be able to advise what rings and bases will be suitable. Some people choose to add a conversion rail from a dovetail set up to a Picatinny set up by adding a special dovetail to Picatinny conversion mount and then to use seperate rings with it.

Whichever set up you go for, don’t forget that you’ll also have to ensure that you choose rings that fit the diameter of your riflescope tube; either 1 inch, 30mm or 34mm, and also the height of your objective bell.

Mounting a Rifle Scope – Step by Step Instructions

Once you’ve ensured that your scope, scope mount and rifle are all compatible, it’s time to follow our step by step instructions for mounting scopes to ensure that your scope is perfectly mounted. Before you go any further make sure that your rifle is unloaded for safety.

Step 1: Make Sure You Have the Right Tools

The first step of optics mounting is to ensure you have the right tools for installing your rifle scope mount and scope. We’d suggest having the following mounting hardware ready:

• Well lit area
• Sturdy gun stabiliser
• Hand tools that fit the screws for your rifle scope mounts
• Torque wrench
• Small bubble level

Step 2: Stabilise the Gun

To ensure that your rifle scope mounting is as level as possible, it’s vital that you stabilise your gun so that you have a stable set up to work on. To do this you could use a gun-vice but we appreciate that not everyone has one of these. Standard work shop vices can work too, but you’ll need some sort of rubber added to it so that it doesn’t damage your rifle. You could also use a sturdy bipod and sand bags or some other set up you’ve come up with to provide a stable platform for attaching your rail, rings and scope. As long as it keeps the gun in a secure, stable location until you’ve finished working on the set up then it should be fine.

Step 3: Mount the Base

Once your firearm is safe and stabilised, it’s time to add the bottom half of your scope attachment set up. The way that you do this depends on whether you’ve opted for a rail and ring set up, or a ring with built in dovetail base set up.

Rail and rings

If you have chosen to use a picatinny rail then this is the first thing you add to your rifle. Before you attach it, we’d advise putting a very thin layer of oil on the bottom of your rail before you mount it to prevent corrosion. Once your base is in place, with the screw holes lined up, torque the screws in with your torque wrench, adjusting them to the manufacturers torque specifications.

Scope ring with base

If you’ve decided on a dovetail ring and base combo then do the same as above with the bottom half of the rings only. 

Step 4: Mount the Rings

If you’ve opted for a Picatinny base rail, then the next step is to mount the bottom half of your rings to it. Use your torque wrench to secure the scope rings to your base rail, ensuring that you tighten them to the recommended torque value.

Once the bottom half of your rings are secured to your rifle, it’s time to place your riflescope into them and then to attach the top of your rings. Be sure to set your scope to the highest magnification before placing it in. Attach the top of the rings loosely with the screws so that you can easily move the scope around to adjust for eye relief and also level it properly.

If you’re using a separate rail and ring set up then make sure not to place them in such a way that they touch the magnification ring or the objective bell. If you’re using a ring and base combo then these will need to be attached in the pre made dovetail holes on your rifle so you won’t be able to move them along the rail to suit your scope. If you have issues with positioning your scope at this point then you may need to reconsider your set up and opt for a rail and ring set up to give you more flexibility.

Step 5: Align the Reticle

When your scope is in place in the rings, do a quick check to ensure that it’s sitting as straight as possible and the reticle is as level as possible when you look through it. We’ll get it accurately level later on.

Step 6: Set Eye Relief

Next, it’s time to make sure that you have the right amount of eye relief. Remove your rifle from your gun vice of other stabilisation option and shoulder it. Look through the scope and make sure that you have a full sight picture with your head in a natural position. If you don’t then move the riflescope forward or backwards a little in the mounts until you do.

Step 7: Level Your Scope

Levelling your scope to ensure that it is level with your rifles action is extremely important or you could face your rifle shooting off target. There are a range of ways to do this but we’d advise using a small rifle bubble level on top of your scopes turret (with the cap off) to ensure that they are both aligned. For added certainty you can also get ones that connect to your rifles action.

Step 8: Tighten the Screws

Once your scope is level with the rifle action, gradually tighten the screws to lock your scope in place. Ensure you make extremely small adjustments to each screw in turn until the recommended torque value is reached.

Focusing Your Scope

Once your scope is properly mounted, use the scopes reticle focus to ensure that the reticle is as crisp as it can be.

Sighting Your Scope

Once your scope is properly mounted it’s time to take it to the range to sight it in. There’s numerous ways that you can sight in a scope but we find the easiest way to do this can be the two step method. For this to work properly, you’ll need:

• To secure your rifle in a bipod with a rear bag to keep it steady
• Be at a range where the targets are around 50-100 yards away
• You’ll need a friend to help you out

Simple steps:

• Take a shot directly at the bullseye. If it hits on target first time then that’s awesome, but chances are unlikely
• Keep your rifle in exactly the same position, don't move it at all
• Get your friend to adjust the turrets to move your reticle until it’s aiming exactly at the point of impact where your bullet hit the target
• Take another shot in the same position as last time. If everything has stayed completely still and you have a good follow-through, your second bullet should be on target
• Take a final shot to ensure your scope has been sighted in properly

Consequences of an Improperly Mounted Scope

Having a properly mounted and sighted in scope is essential to ensure that it is as safe as possible to use, hits on target and doesn’t result in any inhumane shots that cause unnecessary harm to an animal. If you’re at all unsure as to how well you've mounted your riflescope then we always advise contacting your local gun smith for help.

Discover More Helpful Scope Guides 

Mounting rifle scope rings and bases can be daunting, but we hope that our simple mounting steps will give you a guide that will help you to achieve the result you need. If you need any further information about the correct riflescope rings or mounts for your set up then check out our buying guide for rings and bases or feel free to get in touch. You can view our full line of riflescope rings, bases and more here.