Skip to main content
Vortex Diamondback scope

Product review: Vortex Diamondback 4-12 x 40 BDC

Firstly, buying this scope was a mistake. But it’s a mistake I’m very glad I made. I intended to buy the adjustable objective version of the Vortex Diamondback 4-12 x 40 BDC, but ended up with the fixed-parallax type. I couldn’t return to the store and swap it, because I had just left the country where I purchased it.

With the AO version, my idea was to use it at its maximum zoom at a 25 yard range on a rimfire target rifle. However, without that AO bell, the scope just won’t focus at 25 yards at any magnification greater than 8 x or 9 x. So, I reluctantly told my wife we’d need to take this brand new scope off her rimfire rifle and put it on my 6.5 x 55 that was in need of some glass. This is the point where I’m glad this happened.

The technical specs

The parallax setting on this scope is 100 yards – perfect for getting sighted in at the range, and more than adequate for the average hunting shot in the New Zealand bush. The adjustments go out  60 MOA in elevation and windage. With my 6.5 x 55 it was pretty much bang-on at 100 yards, maybe a total of 7 clicks left and a few up or down, I can’t remember. If you’re aiming to shoot long distance (600 – 1000 yards) you’re probably going to want to mount this on a 20 MOA rail.

The Bullet Drop Compensation (BDC) points are graduated in MOA, and so is your turret adjustment. How many times have you bought a mildot scope and found out later it has MOA turrets? So, this is nice to know right off the bat.

Vortex Diamondback scope with caps off.
The turret markings are easy to see from behind the gun.

The turrets are capped and resettable. This is nice, as now that I have my zero I can use the windage or elevation adjustments to my heart’s content without worrying about getting my 100 yard zero perfect again. The caps are nice and low and are easy to grip. Be careful when resetting the zero that you don’t damage the turrets, as I found them to be very tight and had to hold them in place with vice grips while I used a screwdriver to loosen the turret. Any extra pressure while doing this and you could have tool marks on your nice new scope. I covered the surface of my grips with masking tape to prevent teeth marks.

You have a total of 5 points of vertical aim, including the crosshairs and the top of the post. You also have 3 hash marks either side of the crosshairs horizontally, as well as the post edges. How to use the BDC? Check out this video from Vortex.


Quality and ease-of-use

The scope has the usual things that manufacturers claim, such as fog-proof, shock-proof and weather-proof everything. Except, this scope really does. I have mounted two scopes on this rifle – the other I won’t name. The unnamed piece-of-junk was used on one range trip for about 3 hours. Yes, there was wind, rain and sun. When I took it off to mount the Diamondback I noticed that the unnamed scope’s exterior coating was peeling off. After one trip!

Subjected to the same conditions, the Vortex scope still looks brand new. That’s probably why they provide an unlimited, unconditional warranty. Which, to be honest, is half the reason I bought it – that shows confidence!

The clarity was exceptional, and the lense coating wasn’t just for show. I had plenty of light, no glare and just a great shooting experience. The scope also features a fast focus adjustable eye-piece with a decent amount of range on it. This was perfect for when different shooters wanted to try it out. Also, the markings on the turret are easy to see without changing your shooting position much – which is not something I can say for every scope in my safe.

Vortex Diamondback scope on M38 Husky.
Adjustments on the range are done with ease.

Quality of manufacture is something that really shows when you shoot at an outdoor range. It’s also something that greatly determines how long a scope will last and whether you’ll enjoy shooting with it or not. In my humble opinion, the Vortex range is excellent. They are also reasonably priced. In the USA (where I bought mine) they were very affordable. In NZ, they are probably middle of the road. Either way, still worth it for the high-quality optic you’ll be getting. I would definitely purchase another scope from their range.

You also get some handy extras with your scope. There are the standard removable lense caps and a *really nice* cleaning cloth. I would suggest making use of Vortex’s incredibly intricate Long Range Ballistics Calculator. Not only will you be able to figure out your elevation and windage hold, but you’ll probably convince yourself to buy some new rifle while you check out all the ballistics tables you can produce for just about every calibre known to man.

You know the old addage of spend as much on your glass as you do on your rifle? Well, this is one scope that breaks that rule. I would happily mount Vortex optics on rifles that would generally be seen toting the latest Swarovski or Leupold glass.