The .308 (3-0-hate) Winchester is a powerhouse caliber with a storied past and a broad application spectrum. It first emerged in the 1950s and was immediately adopted by the U.S. military as the 7.62x51mm NATO. It became a quintessential caliber for various platforms from the M14, to the M24 Sniper Weapon System, the 240 Bravo, and much more.

The caliber combines substantial stopping power with commendable accuracy over distance, earning its place in hunting, sport shooting, and combat. Paired with a rifle scope a .308 rifle evolves into a formidable, well-rounded tool.

This article aims to illuminate the facets of different rifle optic types, methods of mounting scopes, the specialized realm of thermal scopes, and maintenance to help scopes retain their performance. The .308 caliber with all its capabilities has earned a thorough approach in scope selection.

Understanding .308 Rifle Scopes

The .308 rifle warrants a scope that aligns with the shooter’s goals and the scenarios it will be deployed in. Here we will discuss the diverse types of scopes that can be matched with a .308 rifle, each catering to a specific style of shooting and requirement.

  • Variable Scopes: Variable scopes allow the shooter to adjust the magnification and adapt to varying distances and target sizes. They shine in hunting and shooting environments where engagement distances fluctuate.
  • Fixed Magnification Scopes: Fixed scopes offer a single magnification level for simplicity and durability. These are great for scenarios where the shooting distance remains relatively constant, like competitive shooting disciplines and close to medium-range combat.
  • Long-Range Scopes: Not to be confused with variable scopes or hunting optics, these scopes are truly made for distance targets and may have magnification such as 9-30 power. They will generally have a bullet drop compensator and a compensator for wind drift.
  • Close-Quarters Combat (CQC) Scopes: These scopes feature no or low magnification and are designed to help the user get on target as fast as possible. Red dot sights and holographic sights make up this category. This category will make up the majority of optics for semi-automatic rifles.
  • Thermal and Night Vision Scopes: Thermal and night vision scopes breach the veil of darkness by capitalizing on infrared and light-amplification technology.

Tactical Rifle Scopes

Tactical scopes are designed to assist a shooter with both accuracy and target acquisition in situations where time is a critical factor at close to medium range.

Red dot with magnifier
Red Dot with Magnifier

Tactical optics like red dot sights, low-power variable optics (LPVOs), and holographic sights are crafted to deliver on-demand, uncomplicated aiming aids under dynamic shooting conditions. Similarly, red dots and holographic sights can be paired with a red dot magnifier to help with longer shots.

Pros & Cons of Rifle Scopes

Tactical scopes offer many advantages such as quick target engagement, robust design to withstand demanding use, and illuminated reticles for low-light conditions. These aspects make them favored for close to mid-range engagements, often finding a home on semi-automatic .308 platforms like the AR-10. However, the cons become apparent in long-distance shooting, where the limited magnification and often more superficial reticle designs of many tactical scopes can’t provide the detailed holdovers and windage information beneficial for precision shots at extended ranges.

Long-Range Scopes

Distinguished by their enhanced magnification capabilities and reticle complexities, long-range scopes facilitate accurate engagements at considerable distances, some stretching beyond the 1000-yard mark. Common platforms for these scopes within the .308 realm include bolt-action rifles like the Remington 700 or semi-auto precision rifles like the FN SCAR 20S. Various magnification ranges, such as 5-25x, 4-16x, or even 8-32x, from brands like Leupold, Vortex, and Nightforce, catering to distinct shooter preferences and applications.

Pros & Cons of Long-Range Scopes

Long-range scopes enable the user to shoot precisely at long distances and compensate for environmental factors.  

Their generally larger size and heft might unbalance a rifle, and the higher magnification models offer a narrower field of view, making tracking moving targets at closer ranges more challenging. Furthermore, in fast-paced, close-quarters scenarios, these are entirely useless.

Here, an offset red dot sight can be used in tandem with a long-range optic, providing a quick, close-range aiming solution without needing to adjust the primary optic. This setup provides versatility, accommodating rapid target acquisition at close quarters while maintaining the capability for precision at extended distances.

Offset red dot
Prism Sight with Offset Red Dot

Key Scope Features

When deciding on a scope for a .308 rifle, various elements demand thoughtful consideration to ensure optimal alignment with the shooter’s needs and rifle platform. Firstly, choosing between a first and second focal plane is important; a first focal plane (FFP) scope alters the reticle size with magnification adjustments, maintaining bullet drop compensations and windage lead accuracies at any power setting. In contrast, second focal plane (SFP) scopes keep the reticle size constant. The reticle design itself, whether it’s a simplistic duplex, a detailed Mil-Dot, or a specialized BDC (Bullet Drop Compensator) variant, should cater to the shooting application, balancing visibility and detail. Additional components, such as turret types and adjustment gradations (MOA or MRAD), illumination, and lens coatings, also play a large role in defining a scope’s functionality and performance under various field conditions.

Thermal Scopes for .308 Rifles

Thermal scopes utilize state-of-the-art thermal imaging technology, capturing the infrared light (heat) emitted by objects, and translating it into a visible image. Unlike traditional optics, thermal scopes don’t rely on visible light or require illumination to render clear imagery. Instead, they visualize temperature differentials, effectively penetrating through darkness, foliage, and obscured terrains and providing a stark contrast between the target and its surroundings based on heat emissions.

Advantages Of Thermal .308 Scopes

.308 rifles can benefit from thermal scopes in a multitude of scenarios. For instance, hunters navigating environments with minimal light, such as nocturnal hog hunts or early dawn, will find the thermal scopes invaluable in spotting and identifying games, irrespective of the available ambient light. Moreover, thermal scopes are critical in tactical applications, where identifying and tracking potential threats obscured by darkness or barriers can dictate mission success.

.308 Compatible Scope Mounts

Selecting the appropriate scope mount for a .308 rifle is crucial to guarantee stability and reliability during shooting. Given the wide range of applications .308 rifles are employed in – from hunting to tactical usage – it’s imperative to choose a mount that complements the activity and mitigates any associated challenges.

Weaver-Style Rifle Mounts

For simply target shooting and plinking, the style or rail you use doesn’t matter nearly as much as in other situations. However, one of the most commonly used styles of rifle mounts is the weaver rail. The simplicity, durability, and ease of use of Weaver-style mounts offer a straightforward yet stable platform that resists accidental dislodgement, ensuring a firm scope attachment during such light-duty, general-use activities.

Picatinny Rails

Picatinny rails utilize evenly spaced, rectangular cross-sections, cater to a broader variety of attachments, and are a common choice, especially for target shooting and tactical applications. Their rigid construction and universal mounting options provide a robust platform, particularly conducive for tactical scopes utilized in dynamic environments. The ability to swiftly and securely mount, adjust, or swap out various optics and accessories provides a tactical edge, ensuring the shooter can effectively adapt to evolving field conditions and requirements.

Dovetail Mounts

Dovetail mounts use a classic trapezoidal incision that has been used for a long time, particularly with older hunting rifles and airguns. This more traditional style, frequently found on vintage and European firearms, offers a streamlined, low-profile attachment that limits protrusions, minimizes snag points, and preserves the rifle’s aesthetic lines. While not as adaptable as Picatinny or Weaver-style mounts, Dovetail setups offer reliable stability and a timeless appearance, often appreciated in hunting contexts, where simplicity and tradition hold prominent roles.

Mounting A .308 Rifle Scope – Quick Guide

Mounting a scope to a .308 rifle, while seemingly straightforward, is a meticulous process that demands attention to detail, mechanical proficiency, and a comprehensive understanding of firearm safety and mechanics.

1. Tools & Materials

Torque Wrench: This tool ensures the scope rings are tightened to the manufacturer’s specified torque settings, maintaining stability without over-tightening.
Leveling Kit: Essential for ensuring that the scope is perfectly horizontal and in parallel alignment with the rifle.
Gun Stabilizer or Vise: This keeps the rifle stable during the mounting process, preventing accidental falls or movements that could affect the scope alignment.
Loctite: A thread-locking fluid that prevents screws and bolts from loosening due to vibrations when firing the rifle.
Lens Cloth: To gently remove any dust or fingerprints from the scope’s lens after mounting.

2. Safety

Begin by ensuring the rifle is unloaded and the chamber is clear. Ensure the workspace is clean and well-lit, keeping all tools and materials systematically arranged to prevent any mishaps.

3. Alignment With The Bore

“Bore” refers to the interior of the firearm’s barrel. Alignment with the bore, or bore-sighting, using a 308 bore sight ensures that the reticle of the scope aligns with the bore of the rifle, facilitating accurate aiming and minimizing the number of adjustments needed when sighting in the scope. Manual bore-sighting involves visually checking the alignment by looking through the bore from the breech end and adjusting the scope to align with a distant object. Alternatively, laser bore-sighters, inserted into the chamber or muzzle, can project a beam onto a target, assisting in aligning the scope.

4. Tighten & Secure The Scope Mount

After aligning the scope, commence by gently tightening the screws on the scope rings or mount, ensuring that the scope does not shift from its aligned position. Utilize the torque wrench, applying consistent pressure and adhering to the manufacturer’s specifications regarding torque limits, typically measured in inch-pounds (in-lbs). Once securely fastened, apply a small amount of Loctite to prevent screws from loosening over time due to recoil. Always double-check the alignment and make any necessary micro-adjustments.

The process of mounting a .308 rifle scope requires patience, precision, and adherence to safety. Always ensure that the firearm is safe to work with, and take your time to methodically work through each step, guaranteeing a stable, accurately mounted scope that will serve reliably in the field.

Tips For Choosing A .308 Rifle Scope

Choosing the right scope for a .308 rifle involves assimilating a range of factors, combining your shooting goals and the capabilities of the optic. When navigating through the scopes available for a .308 rifle, a structured approach toward key variables will enhance your decision-making.

The Purpose Should Always Dictate The Scope

Determining the primary application of your rifle sets the stage for scope selection. Whether you are focusing on self-defense, hunting, or a generalized utility approach, the purpose dictates your needs in terms of accuracy, range, and practicality. A short-to-medium range optic with quick target acquisition may be preferable for defense, while hunting might demand greater magnification and a specialized reticle. Always tailor your scope to align with the role of the rifle.

Magnification & Zoom

Magnification pertains to the ability of the scope to enlarge the appearance of the target, while zoom relates to the capacity to alter that magnification, moving between different levels. Variable zoom, such as 3-9x, allows adaptability, providing a broader magnification range to accommodate diverse shooting situations, from close to long range.

Reticle Options

The reticle sets your point of aim while looking through the scope. Specific reticles have additional markings (like BDC or Mil-Dot) for bullet drop compensation or range estimation, facilitating shots at varied distances. In hunting, a BDC reticle could enable swift holdover adjustments for targets at different ranges. Meanwhile, for precision shooting, a Mil-Dot reticle might offer the nuanced control necessary for shot placement.

Objective Lens Size

The objective lens is the forward lens of a scope, and its size dictates light transmission. A larger objective lens allows more light to enter the scope, enhancing visibility in lower light conditions. However, larger lenses can also mean a heavier and bulkier scope, potentially impacting the balance and handling of the rifle. Deciding on the optimal size involves weighing the advantages of increased light against weight trade-offs.

Eye Relief

Eye relief refers to the distance from the rear lens to your eye where the full field of view is visible. Given the .308’s recoil, a longer eye relief (3.5 inches or more) is advisable to prevent “scope eye” (contact between the scope and your eye/eyebrow upon recoil). Insufficient eye relief may result in a limited and unsafe shooting experience, with issues like a black ring around your field of view or a blurred image.

Finding a balance between your shooting objectives and the characteristics of your .308 rifle scope leads to an environment where your equipment complements your goals. Addressing these considerations with the specificity of your shooting style and needs in mind will align you with a scope that enhances your marksmanship and overall shooting experience.

Maintenance Tips For Your .308 Rifle Scope

Reliability and longevity in a .308 rifle scope come from more than just the manufacturing process; they also come from consistent maintenance. Taking intentional steps towards preserving your scope’s condition ensures its performance and avoids hindering your shooting due to preventable issues.

Proper Storage

Ensuring your .308 rifle scope is properly stored when not in use plays a role in maintaining its functionality over time. A padded rifle case prevents potential damage during transportation and from environmental factors like dust, moisture, and extreme temperatures. For prolonged storage, use desiccants to absorb moisture and store the case in a cool, dry area to avoid lens fogging and internal damage to the scope.

Common Mistakes

  • Over-tightening Mounts and Rings: Applying excessive torque when securing the mounts and rings may damage the scope tube, alter the zero, and impact accuracy.
  • Neglecting Regular Checks: Failing to periodically check the tightness of the scope mounts and rings could lead to a shift in the zero and reduced accuracy over time.
  • Improper Cleaning Techniques: Using materials like a rough cloth for lens cleaning can scratch the delicate lens surface, impeding clarity. Employ lens caps when not in use and utilize lens pens or microfiber cloths for cleaning.
  • Ignoring Recoil Effects: Consistent heavy recoil without checking the mount’s integrity and scope can result in internal damage over time.

What is the range of a 308? 

The .308 Winchester can effectively engage targets up to 1000 yards away, though its effective range for hunting is often considered to be around 500 yards to maintain ethical shot placement.

Is a 3-9×40 scope good for a 308? 

Yes, a 3-9×40 scope is versatile and typically well-suited for a .308, providing a practical range of magnification for both short and medium-distance shooting.

How far can a .308 shoot accurately? 

With appropriate optics and in skilled hands, a .308 rifle can maintain accuracy at distances up to 1000 yards, though most shooters will find it most effective in the 200-600 yard range.

How powerful is a 308 rifle? 

The .308 Winchester is renowned for its excellent ballistics, offering a powerful and accurate round capable of handling a wide range of shooting and hunting applications.

What is a .308 good for? 

The .308 is a versatile cartridge, proficient for hunting medium to large game, competitive shooting, sniping, and general marksmanship due to its balance of power and accuracy.

Can you use a 223 scope on a 308? 

While you can mount a scope designed for a .223 on a .308, ensuring it can withstand the greater recoil and offers appropriate reticle calibrations for the .308 round for ranging shots. 

Final Thoughts

The .308 rifle, with its remarkable accuracy, significant power, and versatile application, warrants equally competent optics to harness its full potential. Selecting a scope that complements the attributes of .308 platforms involves a thorough understanding and careful consideration of various aspects. From distinguishing between tactical and long-range scopes, cognizance of key scope features like the first focal plane, reticle types, and objective lens size to dedicated attention towards regular maintenance and adept storage – each element critically influences your shooting experience.

Recognizing the distinct advantages that different scopes and mounts offer and how these can be optimally utilized in varied shooting scenarios forms the foundation of making informed decisions. Furthermore, the knowledge about their specific applications, potential pros, and cons, together with maintaining your scope, leads to lasting performance and reliability in your shooting adventures.

What’s been laid out in this guide forms a comprehensive yet general overview. The world of .308 rifle scopes is profound, with nuances and specificities that cater to a wide spectrum of needs and preferences. Your journey toward selecting the ideal scope intertwines with understanding your unique requirements, whether they are hunting, tactical applications, or long-range shooting.

The best scope for you aligns with your shooting style, desired applications, and comfort. So, immerse yourself in further learning, explore the options available in the market, and may your choice of scope elevate your .308 rifle’s performance to unparalleled heights.

Always feel free to reach out with questions.

The opinions expressed in this post are those of the author and do not necessarily reflect the views and opinions of Tacticon Armament.

3 thoughts on “How To Choose The Perfect .308 Scope

  1. Richard says:

    Excellent article. I have a 700 and a AR-10. I have a 3-9x 40 on the 700. It’s an excellent hunting combo. I have one of your red dots with a magnifier on the 10 and really like the combo. I never thought about off setting the red dot. Definitely gave me something to think about. Thank you!!

    • Jason Ward says:

      Yeah, I know a lot of people who swear by off set red dots. The only downside is you are paying for a second optic. Good thing Black Friday is right around the corner.

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