Vortex Diamondback 4 12×40 – 2023 Review

Vortex 4x12x40 riflescope
Written by Kane Dane

It is always a smart idea to have a trusty scope for your rifle, especially when going long-range hunting. Owning one and having the knowledge to operate the riflescope can prove indispensable when aiming for your target.

A very good option for your medium to long-range hunting needs is the Vortex Optics Diamondback 4 – 12 x 40 Riflescope. This scope can significantly improve your precision when shooting. And above all, you do not have to spend top dollar to get one for yourself.

Product Specifications

Vortex Optics Diamondback Second Focal Plane Riflescopes

  • Aircraft-Grade Aluminum
  • Dead-hold BDC Reticle: Customized dot design
  • Argon purging puts waterproof and fog-proof performance on the agenda
  • Precision-Glide Erector System: Uses premium components in the zoom lens mechanism to ensure smooth magnification changes under the harshest conditions.

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Coming with variable magnification, the Vortex Diamondback Riflescope also offers reliability, durability, and great clarity. It is versatile and comes with several options that always come in handy. Below we will make an in-depth review of all the features the Vortex Diamondback Riflescope offers, and we will also make a comparison with its’ main competitors.


We’ll start off by going through the strengths and different features of the Diamondback from Vortex Optics.  This is a solid scope and we will highlight the reasons that it is.


When you receive this scope, it will be securely packaged in its shipping container.  While the scope comes with just the scope, you’ll need a little more to be ready to use it.  For starters, you’ll need to invest in a set of scope rings to mount this device to your weapon.

vortex package

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The Diamondback Riflescope comes with protective lens caps which are removable and also in the box there is a cleaning cloth.

Design and build

The Vortex Diamondback is a very well build scope. The body is built from a single 1-inch diameter tube of an aircraft-grade aluminum alloy which makes this scope lightweight, very strong, and resistant. The scope features the Precision-Force Spring System construction, which makes it very resistant even to heavy recoil.

vortex Diamondback 4


The surface finish of the body is a black matte anodized finish and is resistant to glare, making it easier to conceal your shooting position. The Diamondback Riflescope is fully waterproof, with quality Teflon resin bushing seals that also prevent dust and debris from entering the scope.

The internal atmosphere is filled with argon gas, making this scope fog proof, and you can easily use it in all kinds of weather conditions.

The Vortex Diamondback Riflescope also features very smooth control. All the moving parts have knurled finish for easy adjustments with your fingers. The windage and elevation turrets have low profile design, have audible and tactile clicks for greater precision, and are resettable to zero.

Optics and reticule

The Vortex Diamondback Riflescope has a magnification power of 4x to 12x, with a 40mm objective lens diameter. The internal optics are fully multicoated, and they transmit up to 91% of the gathered light, allowing for a bright, clear crisp image.

The Diamondback comes with a Dead-Hold BDC Reticule. This reticle is designed with customized dots and made of wire to help eliminate the guesswork when doing holdover and windage corrections. It also has the BDC – bullet drop compensation feature which comes very useful when going a big game or long-range shooting.

This design is based on the second focal plane design. This means that the scale of the reticle remains the ideally-sized appearance, and the hash marks for estimation of range, hold–over, and wind correction remains accurate to the highest magnification.

Specifications and features

The overall length of the scope is 12 inches. The tube length is 5.6 in, the diameter of the tube is 1 in; the eyepiece length is 3.1 in and the eyepiece diameter is 1.69 in. The overall weight of the scope is 14.6 ounces, which does not add much overall weight to your rifle and does not interfere with your aim.

The minimal magnification power is 4x, and the maximum power of 12x. The field of view is 32.4 feet/100 yards at 4x magnification and 11.3 feet/100 yards at 12x magnification. The eye relief is 3.1 inches, and the exit pupil diameter is 10 mm to 3.3 mm (at min and max magnification respectively).

vortex review

The maximum internal adjustment is 60 MOA, for both windage and elevation. The adjustment graduation on the turrets is ¼ MOA per click, and the travel per rotation is 15 MOA. The parallax is adjusted at 100 yards. The adjustment turrets have capped design that allows re-indexing of the turrets to zero after sighting the riflescope. Just remove the protective caps, and while holding the dial, remove the center screw.

Lift the dial of the scope, align it with zero on the index line, and put and tighten the screw back into place while holding the dial. Place protective caps back on and your riflescope is set to go.

Another convenient feature that this scope has is the Fast Focus feature on the eyepiece, making it easy to bring the reticle into focus. The internal mechanisms of the scope are protected with all-climate lubrication for smooth operation under all weather conditions. The zoom lens mechanism has the Precision – Glide Erector System for smooth magnification changes under all kinds of conditions.

Here, we should note that due to the quality build of the riflescope, the maintenance is relatively easy. The interior is protected from the elements, and the exterior has a very durable anodized finish. The cleaning of the exterior should be done by wiping with a soft cloth.

vortex on rifle

The lenses should be cleaned with specific products designed for use on coated lenses. Also, make sure that you blow away any large dust off the lenses before wiping them to prevent scratching of the surface finish. Persistent stains should be removed with a small amount of water or pure alcohol.

You should know that the storing of the riflescope is very important. You want to store it in a dry, clean place, away from direct sunlight.

Mounting and alignment

The Vortex Diamondback has to be properly mounted on your rifle. This is achieved by using the appropriate base and matching rings to mount it to the desired rifle. This particular scope requires 1-inch mounting rings.

It is recommended that you use the lowest ring height to get complete clearance of scope and rifle and to avoid any contact with the barrel, receiver, bolt handle or another part of the rifle. Also, the low mounting will help with the proper cheek weld, and enable a proper shooting position and facilitate faster target acquisition.

vortex mount

After you mount the scope to your rifle, we have some advice for easy adjustment and alignment. You have to do this in order to get the maximum eye relief and protect yourself from recoil. Mount the scope to your rifle with the mounting rings, but do not tighten the ring screws all the way.

First, set the riflescope to the middle of the magnification range; slide the riflescope as far as it goes in the rings. While looking through the scope in normal shooting position, slowly slide the scope back to your face paying close attention to the field of view – stop when you see the full view.

Then, carefully so you do not disturb the front/back position, align the vertical crosshair with the vertical axis of the rifle, either by bubble levels or a reticle leveling tool. After you’ve done this, you can tighten the screws on the mounting rings and you are good to go.

Unique features

The Vortex Diamondback Riflescope is another in a long list of riflescopes available on the market today.

vortex for hunting

However, there are several features that make this product unique in its performance.

  • 4x – 12x Magnification: The variable magnification facilitates its use in medium to long-range shooting. It is easy to use when shooting big game, muzzleloader,s or slug shotgun.
  • Argon-filled, waterproof, fog-proof, and shockproof:  Although all riflescopes in this price range have an internal purging, this one has an argon atmosphere and Teflon resin bushings for improved protection against the elements.
  • Dead-Hold BDC Reticule: Second focal plane Dead-Hold BDC reticle for the elimination of guesswork and precise aim, wind drift correction, and holdover.

Value for money and guarantee

The Vortex Diamondback 4-12x40mm costs approximately 200 USD. This is an excellent price considering the offered quality of build and features.

In terms of the warranty, the Vortex Optic Diamondback Riflescope comes with the Vortex VIP warranty. As the good people at Vortex have stated – the VIP stands for Very Important Promise to the customer.

vortex on rocks

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The warranty covers repairs or replacement of your Vortex product in the event of damaged and/or defective operation all free of charge. If the product can not be repaired, it will be replaced with a product in perfect working order or equal or better physical condition.

Per the promise of the Vortex VIP warranty, it does not matter whose fault the damage was, or where the product was purchased. It offers an Unlimited Lifetime Warranty that is fully transferable; there is no need to keep the receipt, and there is no warranty card to be filled.

We should note here that the warranty does not cover theft, loss, or deliberate damage that doesn’t hinder the performance of the Vortex Diamondback Riflescope.

Main competitors

Now that we have gone over some of the finer points of this scope, let’s take a look at a few of the competitors.  This helps us see how our choice stacks up against other similar scopes that are currently on the market.

Crossfire II Riflescope

Crossfire II RiflescopeThe Crossfire II Riflescope is a similar product in the same price range. This one is slightly more expensive and has some of the same and some slightly different features.

The magnification on this scope is variable and starts at 6x and goes up to 18x, which is somewhat more compared to the Vortex Diamondback 4x – 12x magnification. The objective lens diameter is 44mm. The Crossfire II has the Dead-Hold BDC Reticule, and this also eliminates guesswork on holdover and windage corrections.

The optics are fully multicoated with anti-reflective lens coatings for a brighter view. The internal atmosphere is nitrogen-filled, making this scope fog proof and waterproof. The body is one-piece aluminum construction. The eye relief is 3.7 inches, slightly more than the Diamondback.

The max elevation and max windage adjustment settings go to 50 MOA. The Crossfire II Riflescope weighs in at 19.6 ounces, and its overall length is 13.5 inches. This scope has the adjustable objective or AO, with a parallax set starting from 10 yards up to infinity.

This Riflescope comes with protective lens covers, a cleaning cloth, and a sunshade. Seeing as this is also a Vortex Optics product, it is covered by its VIP Lifetime warranty.

Vortex Diamondback BDC Riflescope

Vortex BDC rifle scopeThe Vortex Optics Diamondback Rifle Scope is another product by Vortex Optics. This scope has a variable magnification that goes from 3x to 9x, with a 40mm objective lens diameter. It features one-piece solid aluminum body construction, for low weight performance and high resistance to recoil.

This scope has 3.3-inch eye relief, which is less than the Diamondback 4-12×40. Its field of view is 44.6 feet/100 yards at the lowest and 14.8 feet/100 yards at the highest magnification. It features the Vortex Dead-Hold BDC reticle for increased precision when aiming at medium-range objects.

The scope has a 1-inch tube diameter, argon-filled internal atmosphere for fog proof and waterproof performance. The adjustment of the capped windage and elevation turrets is ¼ MOA, the travel per rotation is 15 MOA, and the max elevation and windage adjustment is 70 MOA.

This scope also has a fixed parallax setting of 100 yards. Its length is 11.7 inches, and its weight is 14.4 ounces. These features make it a more suitable choice for short to medium shooting ranges.

Basically, the Vortex Diamondback 3-9x40mm Dead-Hold BDC Riflescope has some of the same features as its in-depth reviewed brother, only slightly different intended applications. This scope is also covered by the Vortex VIP Lifetime Warranty.

Nikon ProStaff Rimfire

Nikon Prostaff Rimfire BDCThe Nikon ProStaff Rimfire Riflescope is another good product within the same range. This one is somewhat less expensive than the other ones in this review. This scope features fully multi-coated optics with 98% light transmission for maximum brightness of the image.

The Nikon ProStaff Rimfire has 3x to 9x variable magnification; 1-inch tube diameter body; 3.6-inch eye relief; overall length of 12.4 inches, and weighs 19.2 ounces. Its maximum internal adjustment is 80 MOA.

Unique to this scope is the integrated zero-reset turrets with spring-loaded features for quick and easy zero adjustments. The reticule is a patented BDC with see-through ballistic circles for long-range shooting and allows for a normal sight image for medium-range shootings where the cross-hair acts as the aiming point.

The Nikon scope is protected by a lifetime warranty applicable with a receipt of purchase.


The Vortex Optics Diamondback 4-12x40mm Riflescope with Dead-Hold BDC reticle is a very good scope to have in your arsenal. It has versatile features and can be very helpful in medium to long-range shootings. The scope has durable aluminum construction; sealed internal atmosphere for waterproof and fog-proof performance.

The turrets are also capped for additional protection. The scope has fully multi-coated lenses for increased light transmission, and a bright, clear, crisp image.

Vortex Diamondback

The reticule is Dead-Hold BDC style, with range estimation, and holdover and wind drift estimation. Precision – Glide Erector System for smooth magnification even in harsh conditions. The scope has the Fast Focus Feature for fast reticle focusing, which is especially important, as this is a key feature in the performance of the scope.

The scope has a low–glare black matte anodized finish. This scope is ideal for long-range shooting. The variable magnification comes very handy for big game shooting or when shooting varmint. The scope is sold with lens caps and a cleaning cloth. It is covered by the Vortex VIP Lifetime warranty.


  • Dead – Hold BDC reticle
  • Fully multi – coated optics
  • Fast Focus eyepiece
  • Waterproof, fog  proof, shock – proof
  • Black matte anodized finish resistant to corrosion
  • Ideal for log range shooting
  • Lifetime VIP warranty


  • Needs refocus when changing magnification
  • Short eye relief
  • May get hurt by recoil on high magnification due to short eye relief
  • Little mounting room, does not fit easily on smaller rifles

We have made an in-depth review of the Vortex Diamondback 4-12×40 Riflescope for you, and also have included three additional options you can consider. It is our opinion that this is one of the best scopes for long-range shooting in the around $200 price range.

Vortex Diamondback 4 12x40
  • Packaging
  • Design and build
  • Optics and reticule
  • Specifications and features
  • Mounting and alignment
  • Unique features
  • Value for money and guarantee


The Vortex Diamondback 4-12×40 Riflescope is a very good choice for a long range or big game shooting. It has some nice features for those who want precision, good quality build and comes with Vortex VIP Lifetime Warranty.

User Review
5 (1 vote)

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So, look at the details carefully and make your pick, and tell us your choice in the comments section below.


Kane Dane