Vortex Diamondback 4-12×40 AO

Monday, September 5, 2011

The Vortex Diamondback mounted on my Diana TH56.

Back in March of 2010, I did a blog on scopes, springers, and recoil

In it, I suggested that “if you have been shooting a heavily recoiling springer (or gas ram), and you’ve been noticing your shots sometimes fall exactly where the gun is pointed and sometimes they inexplicably go elsewhere, it just might be your scope reacting badly to the recoil. As a result, you might want to consider changing to a fixed power scope . . .”

Since then, a couple of things have happened.

The first is that I have heard from two people who report that they have had fixed power scopes fail while mounted on an RWS54, which is a heavily recoiling springer.

The second is that on May 1, 2011, I attended a field target match at Eastern Field Target Competitors Club, and there I met Hector Medina. Several things set Medina apart from the crowd in field target competition. The first is that he campaigns a .20 caliber Diana 54 recoilless spring-piston air rifle in the piston class. While the recoilless Diana/RWS springers are rising in popularity in field target, even now you don’t see many of them in competition. It’s also unusual that he shoots .20 caliber when most FT competitors shoot .177.

Medina shooting his RWS54 with the Diamondback scope.

Second, Medina shoots with just a 12 power scope in piston class when most competitors use much higher power scopes.  Third, Medina has done quite well with his rig, taking third at the US Nationals in 2010 and winning the piston class at the Northeastern Regionals in 2011. He says he gets a kick out of the fact that he has done reasonably well using “a squirrel rifle.”

And that brings us, in a roundabout way, to the subject of today’s blog: the Vortex Diamondback 4-12×40 AO scope. Why? Because that’s the scope that Hector Medina uses on top of his RWS 54 for field target competition. Medina has used the Vortex Diamondback 4-12×40 AO for about 14 months now and has put about seven thousand pellets downrange during that period without any problems with the Vortex Diamondback scope. That is high praise indeed, and Medina’s experience speaks well of the quality of the Vortex scope. The plain truth is that you can’t do well in field target competition if you are having problems with your scope.

Based on Medina’s experience, I decided to have a look at the Vortex Diamondback 4-12×40 AO, and the short version of the story is that I am quite impressed. The Diamondback 4-12 stretches just a hair over 13 inches from end to end and weighs just a smidgeon under 15 ounces. It is a variable-power scope with a one-inch tube and a 40mm objective that offers magnifications from 4x to 12x. The eye relief is just a bit over 3 inches, and the focus adjusts from 10 yards to infinity.

The Vortex Diamondback 4-12×40 AO is equipped with the Dead-Hold BDC reticle is a kind of mil-dot lite reticle with just one dot on either side of the crosshairs and three dots below the crosshairs. This works really well for field target, since you can set the reticle up so that the top of your trajectory is at the crosshairs and then work out what ranges the dots below the crosshairs represent. Below is the setup that Medina uses with his gun.

Here is how Medina setup his Dead-Hold BDC reticle. This aimchart is valid ONLY in the gun that originated it: a Diana 54, equipped with an HMO Piston, in 0.20"; cal. firing 13.7 grs. JSB Exacts at 800 fps. Scope is the Vortex Optics DiamondBack 4-12X40 AO DH/BDC on BKL 260-D7 mounts. It is the property and under Copyright of Connecticut Custom Airguns, LLC; no warranties or claims are made to its suitability for other cases.

Besides the BDC reticle, I really like three things about the Vortex Diamondback 4-12×40 AO. First, when I looked through the scope, I thought the optics were really bright and crisp. Second, I found the knurled sections on the objective bell and power adjustment ring were easy to grip. Third, I was impressed with the quality of the elevation and windage adjustment knobs.

Take off the caps on this scope and you find very nice adjustment knobs.

Finally, the Vortex folks must think pretty highly of their scopes: the Diamondback 4-12×40 AO is backed by an unlimited and unconditional lifetime warranty.

Til next time, aim true and shoot straight.

–          Jock Elliott



  1. Andy Stansbury says:

    In your opinion is the RWS Model 56 TH as accurate as the HW97? Since you have had the opportunity to shoot both rifles which would you choose? Thanks.

    1. Jock Elliott says:


      Either air rifle is a tackdriver if the shooter isdoing his or her job and has taken the time to test for the right pellet. I currently own the Model 56TH but not the HW97, so that reflects my personal preference right now.

  2. Jim Lowe says:

    Thanks for the review as I am cotemplating buting one of these scopes.

  3. Tim says:

    Two years later, how is it holding up?

    1. Jock Elliott says:


      Just fine. No issues.

  4. peter says:

    Hi Jock.
    What torque setting do you use on the scope rings for the vortex & Diana 56TH please?

    1. Jock Elliott says:


      I don’t use torque settings. I use an X pattern, moving from bolt to bolt, tightening one eighth of a turn at a time until the bolts are snug.

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