How Far Back to Mount a Scope [Expert Opinion]

We can all agree that mounting a scope in the right spot is essential for accuracy and to ensure you can shoot comfortably. And while it may look like a simple thing, most of us have mounted our scopes in the wrong spot. 

So, how far back should you mount a scope? Find out in the guide below.

For more on specific score recommendations see our list of good scopes for Marlin 336 rifles.

Key Takeaways

• Understanding eye relief is essential in determining how far back-to-mount scope.
• Hunters and shooters can select long or short eye relief scopes based on their hunting or shooting situation.
• Incorrect eye relief can lead to issues like eye strain and pain, distorted images, reduced field of vision, and recoil injury.

How Far Back Should You Mount a Rifle Scope?

When asking the question, “How far back should you mount a rifle scope” we need to talk about eye relief. 

Eye relief is the distance between your eye and the scope. So, why is it important?

If you mount your scope too close to your eye, you’ll strain your eye, leading to imprecise shots. On the other hand, if your eye is too far from the scope, it’ll be hard to see the complete sight image, leading to inaccurate shots.

The scope should be far away from you without casting a shadow from inside the optic. You want to avoid seeing that black ring on the edges of the sight picture.

So, install your scope and place it as far forward as the upper receiver can allow. Get in a shooting position and focus on the scope. Start backing it up until the image through the scope is shadows-free.

For most scopes, standard eye relief is between 3 to 5 inches. Move your head to and from the eyepiece and note how the image appears when you aren’t in the proper eye relief distance. 

Doing so will let you know the right spot for your scope.

Scope Mounting and Eye Relief 

You must understand eye relief to mount your scope in the right spot. 

Most optical rifle scopes have a particular distance range between the eye and the ocular lens where you can see your target correctly. Where you mount your scope should be the exact spot where you can accurately see the target through the scope.

“Political power grows out of the barrel of a gun.”

Mao Zedong

That distance is usually between 3 to 5 inches. If you place your scope in the right spot, the image will appear clear, making it easier to aim accurately. 

In other circumstances, the reticle image will appear off-center, making it hard to place the crosshair on the target accurately. If any of these happen to you, you likely have mounted your scope on the wrong spot and need to reposition it.

Check out this video on how to adjust your scope for proper eye relief:

When determining the proper eye relief for your scope, there are a few things you need to consider:

• Type of gun: Some guns have more recoil, meaning a shooter needs more eye relief to prevent the scope from hitting their eye.
• Caliber: Just like guns, some calibers produce more recoil. That means you need greater eye relief.
• Your position: Shooting from an upright distance requires more extensive eye relief than shooting from lying.
• Scope size: A scope’s size affects eye relief distance, with wider optics needing longer eye relief distance and vice versa.

So, how much eye relief is enough? Well, eye relief will vary from one shooter to the next. The critical thing is that you can maintain a comfortable position when looking through your scope without straining.

There are mainly two types of eye relief, namely short or standard eye relief and long eye relief. Each class is ideal for particular situations. You’ll need to assess your situation and remember your shooting style when selecting eye relief length.

Short Eye Reliefs

“Short” eye relief is also called “standard” relief because you’ll find it in most rifle scopes. The usual length is between 3.5 to 4 inches. 

Short eye relief has a few benefits: it offers a wide field of view (FOV). If you’re a hunter, then you know a wide FOV makes it easier to acquire your target with less movement or effort. This leads to faster shots.

Aside from that, you have to mount a short eye relief scope far back and closer to you. The closer a scope is mounted to the shooter, the better balanced the rifle is. And finally, a short eye relief scope will still give you sharper targets even at high magnification.

Here’s an important question: Who should consider a short eye relief scope?

A short eye relief scope will be helpful if you often shoot over short distances or in heavy vegetation covers. You’ll get a wide FOV, perfect for hunting your game in heavy vegetation.

I mentioned that some guns or calibers have more recoil. Be careful when using a short eye relief scope if you have such a weapon. The chances of returning home with a bruise are high because the scope is closer to your eye and can lead to recoil injury.

Long Eye Reliefs

A long eye relief scope is any scope with an eye relief distance longer than 4.5 inches. Most of them start from six inches going up. Today you’ll find plenty of scopes with long eye reliefs. These rifle scopes are usually mounted close to the rifle barrel or shotgun.

Although your weapon may look awkward, there are several benefits to mounting a scope near the barrel.

For example, shooting behind such a weapon is more comfortable because you won’t need to strain too much to find the right spot for a good sight picture. The less tired you are, the more fun you’ll have at the shooting range.

Moreover, mounting a scope further down the barrel is very beneficial when shooting bolt action rifles. You can easily load rounds for follow-up shots much more quickly. You can also use large caliber rifles with these scopes without worrying you’ll bruise your eye.

“It is one of the great joys of home ownership to fire a pistol in one’s own bedroom”

Alfred Jarry

Before getting too excited about these scopes, they have a few drawbacks. The highest magnification you’ll get is 8X, which is a little small. These scopes are ideal for short-range shooting or circumstances that don’t require maximum shooting.

Unlimited Eye Relief

You’ve probably come across specific optics labeled unlimited eye relief before. These aren’t the usual scopes with lenses. In most cases, an optic labeled unlimited eye relief is likely a red dot scope, digital rifle scope, reflex scope, or holographic optic.

Each of these has a particular aiming technology. Reflex red dot sight and red dot scopes don’t have any magnification. They use an illuminated red dot to help the shooter acquire their target.

Holographic sights use lasers to project a reticle image, and digital rifles scopes, also known as smart scopes, use video technology to reflect a sight picture on a screen instead of using lenses.

Can You Adjust Eye Relief?

No, you can’t adjust eye relief on a scope. As mentioned, you either get a short eye relief or long eye relief scope.

But you can adjust the scope itself so that it’s either mounted close to you or far. You will know you aren’t within your scope’s eye relief if the image is out of focus, blurry, or obstructed by the black ring in the scope. 

Before you start adjusting your scope for adequate eye relief, be in a comfortable shooting position. Hold the rifle on your shoulder and ensure you’ve achieved a proper cheek weld. Then adjust the position of the scope until you achieve adequate eye relief.

For similar reading see our post on the different types of rifle scopes.

FAQs

Can you mount a scope too far forward?

You can mount a scope too far forward, preventing you from seeing a clear image through the scope. Even long eye relief scopes have a limit. Mounting a scope too far forward will prevent you from seeing a clear and full image.

Can you mount a scope as low as possible?

You can mount a scope as low as possible. In fact, gun experts recommend doing so as long as you ensure it doesn’t touch the receiver or barrel.

Where should your scope be mounted?

You should mount a scope where you will achieve adequate eye relief. Because each scope has a specific eye relief distance, ensure when you mount your scope, you are in a comfortable shooting position and your eye falls within that eye relief distance.

Can you mount a scope too far back?

You can mount a scope too far back, preventing you from seeing the image clearly. If you must pull your head back to see a clear FOV, that means you’ve mounted your scope too far back.

References

(1) Richard Douglas, Eye Relief: Everything You Need to Know. Retrieved from https://www.bushnell.com/through-the-lens/bu-blog-eye-relief-everything-you-need-to-know.html