• Manufacturer: Leupold
  • Model: Mark AR MOD 1 6-18x40mm
  • Model Number: 115394
  • Finish: Matte Black
  • Magnification Range: 6.5 - 17.1x (Actual)
  • Objective: 40mm
  • Tube Diameter: 1"
  • Eye Relief: 3.7 - 4.9"
  • Click Value: .1 MIL
  • FOV: 15.2' - 6.7' @ 100y
  • Adjustment Range: 67 MOA - Elevation
  • Reticle: Mil-Dot
  • Focal Plane: 2nd
  • Weight: 15.3oz (433g)
  • Overall Length: 13.5" (343mm)
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Leupold optics has a huge array of different scope offerings, everything from lower end hunting scopes to very high end tactical scopes. We have reviewed a couple of them here at Sniper Central and have extensive experience using many of them on everything from M24s to Barrett M109 SASR rifles. But we have not even come close to covering all of the available options from Leupold for tactical long range rifles. This time around, we are trying to capture something on the lower end of the available tactical scopes from Leupold. We wanted to see how a more affordable scope may work out for a long range tactical scope. We wanted to stick with their Tactical lineup of scopes as they have all the normal features we would desire for a basic tactical scope, so we went to their lowest priced offering, the Mark AR series of scopes. These scopes are made specifically for AR rifles, hence the name, but we wondered if one of these AR scopes could work on a long range rifle? We were originally going to take a look at the more affordable and probably best overall option, the version, but due to a mixup in ordering and a swapping of scopes, we ended up with the 6-18x40mm version. They are similar in function and features, so we elected to stick with it and review this higher powered version.

The official name of the scope is the Leupold Mark AR Mod1 6-18x40mm. The Mod 1 is a key distinguishing factor as they replaced the original Mark AR series with these modified Mod 1 versions with many important changes that we will outline during this review. The scope arrives in a traditional Leupold tactical box and includes some handy little booklets that explain the functions of the scope and how to use their tactical reticles. These are the normal booklets that are included in all of the Leupold Tactical line of scopes. There is a sticker and some other items included like a small Allen wrench for slipping the knobs, but do be aware the Mark AR series does not include any flip up scope caps like the other higher end tactical scopes from Leupold. It also does not include a sunshade, normal for Leupold, but they can be purchased separately.

The Mark AR scopes have a 1″ diameter tube, which today is somewhat of an anomaly for tactical rifle scopes as the trend continues to move toward ever larger tubes and scopes for use on sniper rifles. With a 1″ tube and even with the larger 6-18x magnification, the scope appears and feels small and light compared to most tactical scopes out there today. We recognize the need and importance of having enough capability and functionality, but we do prefer light and compact as well, provided it brings the goods in terms of capability. We also like to see the made in USA tag with the scope as well. Some of the very high end tactical scopes from other makers are being made in the USA now as well, but it is also nice to see that Leupold’s mid range scopes continue to be made in the USA.

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The eyepiece on the scope uses a non fast focus eyepiece with a lock ring, which has long been used on most Leupold scopes. This fine adjustment is certainly slower to focus exactly right for your eye versus the fast focus setups found on other scopes, but you only do it once, then set the lock ring and you should be good from there. To adjust that reticle focus, the entire eyepiece rotates, there is no separate ocular housing that rotates from within the eyepiece housing itself like is traditionally seen on fast focus setups. One system, fast or fine focus, isn’t better than the other, they are just different and it depends which functionality you desire as to which is preferred. The threads on this Mark AR are tight and there is no loose or wobbly movement of the eyepiece.

Just in front of the lock ring on the eyepiece is the zoom magnification control ring. This ring is knurled to provide a nice gripping surface in all weather conditions and there is a larger protrusion as well for the thumb or fingers to easily grab and help rotate. It is the more simplified version of the throw levers available on other scopes, though it is not as large in this case and is common on scopes. The power ring is nicely marked for the zoom powers with the numbers tilted to face the shooter in a manner to make them easier to read from behind the scope. With the reticle located on the second focal plane, this is important for the user to be able to quickly determine if the scope is on the correct magnification to perform range estimation. The power ring requires a low to moderate amount of force to rotate and it is smooth through the entire range which covers about 90 degrees of rotation from 6x through 18x.

The 13.5″ length of the 6-18x version of the Mark AR scope is the longest of the four available options which include the 1.5-4x, 3-9x, 4-12x and 6-18x. This longer tube is needed for the higher magnification but it is also handy for providing a generous amount of mounting area for the rings. In front of the eyepiece and past the area to mount the rear ring, rests the elevation and windage knobs on top of a fairly small elevated shoulder. Perhaps the most important part of the Mod 1 versions of these scopes that replaced the original Mark ARs, was the including of what Leupold calls the P5 knobs. The original Mark AR scopes had different knobs on some of the versions that had dust covers and were in .25 MOA clicks. The P5 knobs are a lower profiled external tactical style knob setup with .1 MIL clicks to match the available mildot reticle, which our scope has. There is an aggressive knurling on the top of the knob that provides plenty of texture for gripping in adverse weather.

Because of the size of the knobs, there is not a lot of room for the printed markings and the numbers are fairly small, but there are little hash marks at each .1 MIL click with numeric markings at each whole number and half number. There are 6 MILs of adjustment per revolution which is enough to take a 175gr match .308 from 100 to just about 700 yards (depending on atmospheric conditions) in a single rotation. The clicks themselves are pretty good, they have a positive tactile feel without any slop or movement between clicks. They are not audibly muted, so there is a click that you hear as well. We typically prefer a muted click like the M1 knobs, but these ones are not too bad. The scope has a decent amount of elevation adjustment, 67 MOA total, or just a bit over 19 MIL, which with a canted base allows for a good amount of elevation for 1000+ yard shooting with a 308 and 100 yard zero. Unfortunately, there are no little hash marks under the elevation knob to help you keep track of how many rotations you have gone past zero. We would like to see those.

Looking at the picture (remember you can click on all photos to see an enlarged photo) you will notice that the elevation knob has Bullet Drop Compensator markings above the standard click marks. Since these scopes are intended for AR rifle use, they come from the factory with a BDC knob set for a standard .223 55gr load at 3300 fps. Of course, we are not using this scope on a AR or a 223 rifle, so the BDC is not very useful for our purposes. Since we were planning on use this scope on a dedicated rifle, which is chambered in .308, we decided to go through the Leupold Custom shop and have a new elevation dial made for the scope with our exact load and conditions that we expect to us the rifle in. The Leupold custom shop is good to work with and they charge $60 to have the knob made for you and it usually takes about 4 weeks to get them. If you already have the scope and are looking for a knob calibrate for the 308 168gr match load, we actually have them already made up and ready to go in the store, just follow this link.

As you can see in the picture below, we received our BDC knob calibrated for the standard NATO M80 load, this was done for a new article, evaluation, review, and concept we will be writing up in the very near future. You may notice on the new knob that it says it is calibrated for .25 MOA clicks and not .1 MIL, this was our fault. We failed to specify when we ordered it that this is for the new Mod 1 version with the P5 knobs, so we got one for the old version of Mark AR. A new BDC knob will be here shortly. The interesting thing about the custom knobs is that they come with a zero stop, which at first we thought was great. It works very well as a zero stop and is a very simply design. But, there is a draw back, the zero stop works going the other way as well, meaning that it prevents the knob from going past a single rotation. This handicaps the scope to only allow 100-700 yard shooting with a 308. There are a couple of things that can be done to address this issue. You can use the normal knob and just use the standard markings on the bottom and ignore the BDC. Or, you can just tell the custom shop when ordering your new knob that you do not want the zerostop installed on your knob. Or another alternative is to have the knob made with a 200 or 300 yard zero, you would then hold low at shorter ranges and then you can have a knob that goes from about 300-800 yards. Another alternative is to have a custom dial made by Kenton Industries who has several different dial styles available versus the Leupold.

The windage knob is the same size and shape as the elevation knob and it has the same nice clicks, though that includes the same audible click as well. The markings go up in both directions which we prefer and there are arrows that indicate which direction is both right and left. We would also like to see a little L or R next to the actual number to indicate which direction you have already dialed into the scope, but this isn’t critical. Like the elevation knob, there is 6 MILs of adjustment per revolution, which gives you 3 MIL before the numbers overlap. This is enough windage adjustment to allow for shooting a 308 in a 10MPH direct crosswind out to a bit over 1000 yards without overlapping. Of course, if shooting in stronger winds, that crossover will happen sooner than that, but this is still a decent amount for these smaller knobs.

As is probably obvious when looking at the photos, there is no side focus on these Mark AR scopes. For cost reasons, these scopes are built on the lower priced 1″ tube design that Leupold has and they do not make a side focus setup with their 1″ tube scopes. Instead these scopes are a bit old school and have the adjustable objective up on the bell as many of the hunting style scopes do. Only the 4-12x and 6-18x Mark AR scopes have an adjustable objective. The adjustable objective being located up on the bell is actually not a problem and in fact it can be argued that it is a more precise and accurate setup for adjusting the parallax, but it lacks the convenience and accessibility of a side focus. Once you get used to reaching up to the front of the scope to focus it, it actually becomes quiet easy and not much of an inconvenience, but we do have to point out that it is an additional reach and causes additional arm movement. This is bad because we as snipers, like to avoid as much movement as possible for the sake of concealment. Yes, this arrangement can work just fine, but for tactical reasons we still prefer a side focus. The focus ring itself rotates smoothly through the entire range and works very well to get a nice clearly focused sight picture. There is also some knurling on the focus adjustment ring, which provides a very good gripping surface but more so it also provides a tactile indicator that your hand is on the focus control which is handy when you are keeping your eye on the scope picture and reaching to make the focus adjustment. There are range markings on the focus ring where it is calibrated to be parallax free, but there is no way to see those markings from behind the scope. The best practice is to just focus the scope using that focus ring until the picture is sharp and clear, and then go with that. Also, only the focus ring rotates, so the bell in front of the ring remains stationary which allows for the easy use of some butler creek flip up caps.

Overall the scope has a nice look to it and with a 1″ tube and 40mm objective, everything is smaller in scale than the traditional large tactical scope. The matte black anodized finish appears to be high quality and evenly applied and adequately thick over the entire scope. The markings are mostly subdued, but there are some white Leupold logos on the windage knob that stick out a bit, but the rest of the markings are nicely applied and readable. The scope does not come with a sunshade or flip up scope caps, but both are available.

The Mk AR 6-18x is available with either a standard duplex reticle or the mildot reticle, and of course we opted for the mildot in order to provide some range estimation capability. The dots also can conveniently be used for hold offs and hold overs. The 1.5-4x and 3-9x have an illuminated reticle option as well, but not the 4-12x or 6-18x. With the knobs in MILs and the reticle a mildot reticle, it puts both the reticle and the knobs in the same unit of measure, which many shooters prefer. The reticle is located in the second focal plane which means it does not grow or shrink when the zoom power is changed and that the reticle is only accurately represented at one magnification power. Leupold has always used, when possible, the highest magnification setting as the correct power for their reticle size on their second focal plane scopes. So to use the reticle correctly, the operator would zoom the scope all the way in to 18x with this scope. The actual max zoom power on this scope is 17.1x, and the reticle is calibrate for that. In reality, most scopes do not actually have the exact magnification that is specified in their title, Leupold is just actually willing to print the actual magnification power if you look at their specs. Though if you ask us 17.1 sure seems a lot closer to 17x than 18x.

With the detailed examination of the scope completed, it was time to begin the operation review of the scope. The first step in this process is to actually mount the scope to the rifle. As we mentioned in the beginning of this review, the scope was selected for use on an actual specific rifle which is a semi-custom Remington 700 chambered in 308 and mounted in a McMillan Winchester Marksman stock. You will be seeing this rifle in several write-ups coming up on Sniper Central. We used a Leupold Mark 4 one piece base mounted to the action with the normal provided screws. The Mark 4 base has a 15 MOA cant which helps maximize the up elevation in the scope. We used a set of Leupold Mark 4 1″ medium height steel rings which are the lowest height rings that Leupold manufacturers. The rings and base are very high quality and everything mounted up very easily and smooth. With the small 1″ tube and 40mm objective, the scope mounts nice and low which has become the exception instead of the rule on tactical rifles. The large tactical scopes popular today require higher and higher mounting in order to clear the scope from the barrel. It was nice to mount everything nice and low and keep a smaller profile allowing the rifle to be used without any sort of elevated cheek rest.

The optics on the scope are very good for this price range, but most modern scopes, even the cheapest ones, have good glass, especially compared to scopes 30 years ago. The picture is bright and clear and the controls worked very well to get a nice sharp reticle and a crisp image. The contrast was also very nice and the focus knob worked effectively to focus the image and to insure parallax was not an issue. You can test parallax by focusing on a target and then moving your eye side to side to see if the reticle moves on the target. Once properly set, it was good to go. We have mentioned the virtues of a smaller objective, such as smaller size and lighter weight and being able to mount the scope lower, but there are negative attributes as well. The light gathering capability is reduced, though quality glass can make up for that, and it also creates a smaller exit pupil, which can become noticeable at higher magnifications. With a 40mm objective and the power set to 18x, the exit pupil comes to 2.3mm, which is a fairly narrow band of light to align your eye with. This means that there is less room for error when aligning your eye with the scope, which in turn means it is easier to inadvertently see scope shadow along the edges. We didn’t notice it being a problem with our use of this scope, but just be aware it can be a factor.

We also mentioned that because this scope is setup for an AR platform, it is designed with a longer than normal eye relief. At 6x it is a long 4.9″ and it goes down to 3.7″ at 18x. This can be an issue when first mounting the scope as you may have to mount it a bit further forward than normal. With modern one piece rails this is not an issue as you can easily move it forward a slot or two. Once mounted there is a generous amount of leeway for a full sight picture when placing your head behind the scope. During the initial mounting, be sure to set it up when in the prone position and cycle through the entire magnification range to be sure you get the position set to the location best suited for your use.

For the shooting portion we fired the rifle over several sessions which included some overcast skies, temps between 40-50 degrees F, and winds from 3-7 mph. All-in-all these were pretty good shooting conditions to test a scope. First up after zeroing the scope, which was quick and easy, was to fire the scope through the box to test tracking and repeatability of the elevation and windage controls. It has been a long time since we have seen a scope fail this test, and we are happy to report that it will be longer still as the Mark AR did just fine and the box looked very nice with the fifth group right on top of the first. We then move on to testing the size of the clicks themselves by firing a group, then dialing in 6 MIL of left, fire a second group, and then come back 6 MILs to the right and fire a third and final group which tests repeatability of the adjustments again. We then measure the distance between the first and second group to see how accurate the clicks are over a fairly wide range. When complete, the third group was again right on top of the first showing good repeatability of the internal adjustments. When measuring the distance between the first and second groups we allow for some error because the group sizes are never a single hole and the rifle/ammo combo introduces some error to the test. Anything within 5% error is considered passing, and we consider sub 3% error as an excellent score and right on. At 100 yards the distance should be 21.6″ between the two groups. The distance with this scope measured 21.70″ from center to center, which gives us an error of 0.5%, which is an excellent score. We do want to mention that the combination of the scope having a decent amount of down elevation dialed in because of the canted base and taking into account some windage that was needed to be dialed in for the initial zero, when we dialed in the 6 MIL of left, the knob was starting to get a bit stiff indicating it was getting towards its left max. There was no operational concern with this, but it actually was good to see the clicks were still very precise even when pushed to the limits.

After testing the internal adjustments and shooting the scope, we wanted to test for reticle shift with both the zoom adjustments and also the adjustable objective. For these tests we use a bore sighting optical device and align the reticle at a precise point and then watch for any reticle shift when cycling through the zoom and focus adjustments. The reticle shifting can be a problem with lower quality scopes and can cause some major problems when long range shooting. First up was the zoom power test and we are happy to report that the reticle was solid through the entire range. If there was any movement, it was so small we couldn’t notice it. The adjustable objective test was also very good. There was a tiny bit of down movement in the reticle at the very extreme low end of the adjustable objective range, when focusing at 25-35 yards. Everything above that, which obviously is where 100% of your shooting happens as a sniper, was rock solid.  We have been surprised to discover that more scopes struggle with reticle movement with the adjustable objective than with the zoom test, but the Mark AR did very well on both.

So after all of this testing and evaluation of this scope, are we ready to sign off that this lower end Leupold tactical scope can be used for serious sniping? We would say yes, but with a caveat. That main caveat is with the elevation knob. The scope is functionally capable of handling the job and is a good quality scope at a good price. But because Leupold is targeting the scope for the AR market, it has hindered the capabilities a bit. The 223 BDC knob that comes with the scope is usable for other calibers only if you use the tiny markings on the bottom of the dial as you would a traditional dial. Otherwise you can order a Leupold custom dial, which is a good option, but they only mark the dial for a single rotation of adjustment, which limits it to 100-700 yard shooting with the 308. If the zerostop is not installed, you can rotate past the first revolution, but the markings are difficult to track after that. With a standard custom BDC with zerostop installed, it actually would make a great DMR setup, even on a bolt gun. For this scope, we have ordered a Kenton Industries knob in their “military” format which has two levels of markings to get us to 1000 yards with the M80 military load. This should make this scope more feasible in a sniper role. The scope is a good size, the controls are easy to use and accurate, and while we prefer a side focus, the adjustable objective up on the bell is at least usable. Another nice thing about this scope is that it is backed by Leupold’s life time warranty and world famous customer support. No, it is not on the same level as the high end tactical scopes on the market today, but it has its own advantages and works as needed at a more affordable price. We are planning on keeping it on this rifle and seeing how it does during more serious sniping use.

Sniper Central


SP Perry

Leupold sent me a mil adjust elevation dials that are used on their Patrol scopes & they work just fine on the 6-18X40 AR scopes. I have 4 scopes of this kind. The elevation dial fell off 1 of my scopes while I was using it at 15 deg. temps & now it back at Leupold being fixed. These are OK scopes but lack serious durability. Good glass for shooting rodents in bad light. Leupold has discontinued them.


No reason was given, but they are in this business to make money, so I suspect it was just a dollars and cents decision. If they are not selling enough of them, they change and move on.


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