Supporting the second amendment by using the first.

Leupold Mark AR Mod 1 and Vortex Viper PST Review

Leupold Mark AR Mod 1 1.5-4x in a Leupold Mark 2 IMS mount next to a Vortex Viper PST 1-4x in an ADM recon QD mount.

The world of low power, variable magnification optics can be a confusing place with so many options being offered. Recently I needed a new scope for a rifle build and decided it needed one of these offerings but I didn't have a clue where to start. Research time.

Like the majority of casual shooters I cannot afford top-tier optics. Companies like Nightforce, Schmidt & Bender, and US Optics all make very nice equipment but it is all unfortunately out of my price range.  So in keeping with the mantra of 'buy the best gear you can afford' I was stuck solidly in the mid-level options. 

After doing some research I was left with the following candidates.


Vortex Viper PST 1-4x $500 9.7" 16.2 oz
Leupold Mark AR Mod 1 1.5-4x $400 8.5" 9.6 oz
Burris MTAC 1-4x $350 11.3" 17.0 oz
Primary Arms 1-6 Scope 1-6x $270 10.75" 17.4" oz


I chose to pursue what I believed were the best of these options -- the Leupold Mark AR Mod 1 and the Vortex Viper PST 1-4x. This is a comparative review of those two optics.


How do they look? When comparing scopes one of the most commonly talked about aspects is the ability of the lens to gather light, and consequently the apparent brightness and clarity of the image shown therein. These two products look great with very little difference between the two save for one thing.  Compare the clarity of the images near the edges.  Notice how the Leupold gets a bit fuzzy around the edges while the Vortex boasts a crystal clear image, edge to edge.

I initially thought this was my camera, my poor photography skills, or a combination of the two.  However, all of the photographs I took showed a similar discrepency between the two which ruled out that theory.  It was a persistent difference.

Vortex wins in the image clarity realm.


Looking through each scope on the lowest magnification setting. Vortex left, Leupold right.


People talk a lot about the 'true 1x' low end on these scopes. This isn't something I seek out but I will discuss it for the purpose of helping you make an educated decision. The Leupold doesn't even attempt to hit the 1x mark, starting their magnification range at 1.5x. It is usable with both eyes open as the image presented to the dominant eye takes precedence, at least for my brain.

The Vortex is honestly the closest to 'true 1x' that I've ever seen. With the illumination activated it functions as a red dot with some eye relief. +1 for them.

Looking through each scope on the highest magnification setting. Vortex left, Leupold right.


This was an important factor for me. The major drawback of magnified optics on a carbine or rifle, as opposed to reflex or holographic sights, is the need to position your eye in the exact position required by the scope. Most people with an AR-15 type rifle like to think it would function as both a medium range shooter and a useful close-quarters defensive tool. This is inhibited by the time required to find proper eye relief of your scope as opposed to, say, an EOTech where you just point and go regardless of how close or far your face is from the optic.

The following table indicates both the minimum and maximum distance from the focal lens that the eye must reside to maintain a clear, full sight picture, as well as the range between those two numbers. I found both scopes offered good ranges of eye relief and had no trouble maintaining a nice, clear sight picture. The Leupold does offer a greater range here so it wins points for that.


Vortex 1 ¼" 3 ¼" 2"
Leupold 1 ¾" 4 ¼" 3"


Let me preface this section by saying that reticle illumination is not an important feature to me, as it is something I rarely use and almost never need. To some people however it can make or break an optic. To each their own.

The Leupold features a more traditional cross hair with BDC markings and a circle in the center. I purchased the more expensive version of the scope that features the SPR FireDot reticle. This gives the user the ability to turn on a very sharp, bright green dot in the center of the reticle. On the highest settings it can be almost too bright creating some mild glare.

The control for this is the worst part of this optic. To enable the illumination, you first unscrew the battery compartment cap slightly which then releases pressure on the button built in to the cap. This enables the ability to actuate said button which you then use to toggle between brightness settings. After setting it to the desired level the cap screws back in to 'lock' your setting in place. Not only is this counter-intuitive and cumbersome, it is prone to problems. I've encountered the same issues most other reviewers of this scope have reported with the illumination activation being very finicky.

My version of the Vortex scope features what they call their TMCQ reticle. The illumination is controlled by an intuitive adjustment knob on the focal lens housing with 'off' positions between each brightness setting, allowing you to leave the illumination turned off yet only one click away from your favorite brightness setting. Very clever. The illumination is exceedingly crisp and contours very nicely presenting an excellent sight picture.

The reticle markings themselves are far more advanced than what I can possibly use just shooting targets at fewer than 150 yards. They are somewhat small and may be hard to read for those with less than perfect eye sight. That being said Vortex did an excellent job of combining an advanced reticle with a simple one and enabling quick usage with the circle and dot.

Vortex wins the reticle comparison without a doubt.

A view of the illuminated reticles.  Vortex left, Leupold right.


Both of my models feature exposed turrets making quick adjustments easy. The turrets on both models feature very positive clicks on adjustment. The Vortex clicks feel more 'rounded' but solid while the Leupold feels more fine and precise, but the clicks on the Leupold are so light that you are more inclined to accidentally over-adjust.

The illumination control on the Leupold is dismal as stated earlier, with the Vortex having a control that is not only intuitive to use but very cleverly designed.

The magnification control on the Vortex is extremely tight and frankly difficult to use, especially on a cold day with gloved hands. This could be remedied with a 'cat tail' throw lever.  In fact, Vortex is marketing their own called a Switchview Throw Lever (SV-1 and SV-2). The Leupold' magnification adjustment knob has a raised bump that makes it easier to turn.

I'll call this a draw. Both have their ups and downs.


This was a big selling point for me. I've been dissatisfied with these types of scopes in the past delivering mediocre results for the massive size and girth they have (looking at you, Millet DMS) so I wanted this one to excel.

The Leupold simply blows all of the competition away in this department. You sacrifice having a 'true 1x' low end of the magnification range but in exchange you get a scope that is just over half the weight of the competition. If weight is important to you in this application, you cannot beat the Leupold in this price range.

The Vortex features typical size and weight for this optic type in this price range.

+1 Leupold


These are both great options for the intended use and frankly you can't go wrong with either. If weight is a concern for you the Leupold simply dominates. If a little extra weight is not a concern, the Vortex is superior in nearly every other aspect.

If you decide the Leupold is right for you I would forgo the illuminated reticle and save yourself ~$130.


An authorized full-line Vortex dealer, A&A optics sells only the finest scopes and optics at highly competitive prices.
Visit A&A Optics on the web.
Written By: Ryan Brotherton
An avid shooter and gear head, USPSA member, certified NRA handgun instructor and amateur gunsmith. He created to support the second amendment and establish a modern environment for firearms reviews and news.
Read more articles from Ryan Brotherton