Exclusive Review: Leupold Mark 6 1-6x20mm Riflescope

Then we saw the Leupold Mark 6 1-6 x 20 at SHOT Show this year. It's slightly smaller and lighter than the CQBSS but provides 70 percent of its cousin's capability at half the price. Its 1-6 magnification is optimal for close and intermediate distance engagements. This makes it ideal for combat carbines, both light and heavy. The zoom range, size and weight of the Mark 6 is going to have the growing number of 3-gun competition shooters salivating.

Leupold lent us the first unit off the production line for a review, a month ahead of anyone else. So, while other outlets are getting the first chance to put Round One downrange this week, we're giving you a full-on field evaluation after weeks of testing.

GearScout contributor, heavy carbine SME and SOCOM veteran, John McPhee and I had the Mark 6 for three weeks and ran 2,750 rounds with it during several range sessions on the east and west coasts. The 2,590 rounds of 55gr and 77gr 5.56mm and 160 rounds of M118lr .308 gave us a good chance to see how the optic could run switching between my 16" Mega Arms/Daniel Defense 5.56mm carbine and John's 16" .308 KAC SASS Carbine.

more[singlepic id=4656 w=320 h=240 float=yes]It's worth noting that our Mark 6 came with the CMR-W reticle optimized for the M118lr 7.62 175gr round, but the bullet drop compensating elevation dial was set up for M855 5.56 62g rounds. This has no bearing on the accuracy of the optic, but it's worth mentioning because it allowed us to evaluate the accuracy of both the CMR-W reticle holds and the BDC turret markings in 5.56mm and 7.62mm.

[singlepic id=4668 w=320 h=240 float=yes]We used a LaRue LT-104 cantilever mount that fit the Mark 6's 34mm tube perfectly out of the box. Before settling on the LT-104, I tried using a set of rings, but I found the front ring wanted to straddle the joint between my upper and the DD Omega X Rail 12.0 hand guard. I didn't like the idea of using the hand-guard rail for an optic evaluation. I thought the optic spanning the hand guard would just add a needless complication should anything go wrong, so we went with the LaRue. The LT-104 offsets the base of the mount from the optic and allows it to be mounted farther forward without running off the front of the upper's flat top. More on the mount later.

After leveling the scope, we torqued the mount rings down to 25 inch-pounds. Nothing bent, cracked or dimpled. Focusing the Mark 6 was painless, and there's no need to mess with parallax adjustments since there aren't any on this short-range optic. Eye relief was exactly as it says on the box -- 3.7 inches -- which placed the objective just above the charging handle on my AR.

Punching paper at 100 meters with no wind and the sun at our backs, we took our time zeroing the optic and measuring the turret movements with the optic at max magnification. Before shooting anything, we ran the dials back and forth a bunch to make sure everything was seated. Using 77gr Black Hills ammo, we zeroed in four shots, slid the turret sleeves to dial in our zero and moved on to verifying the accuracy of the turret movement. We shot the 5.56mm gun from an Atlas bipod and a sandsock at a calibration target.

[singlepic id=4657 w=320 h=240 float=yes]Holding the aiming point at the base of the target, we advanced the elevation dial 1 milliradian at a time and did the same for the windage. Accounting for shooter induced error, this gave us a dead sexy line of vertical and horizontal holes spaced at 10-cm intervals. This confirmed the accuracy of the mil markings on both dials.

We measured 11.4 mils of elevation travel in 57 clicks using 114 cm of target. Our windage findings were similar: 5.6 mils and 5.4 mils of movement on either side of the zero in 28 clicks right and 27 left.

Leupold specs list the scope as having 11 mils of movement in one dial rotation, lock to limit; we counted 11.4 mils of elevation and 11 mils windage. So, out test scope came with an extra 2 clicks of elevation for free. Our test showed the locking turrets are calibrated precisely, and we later found they could be trusted out to our max engagement distance of 650 meters.

No Military Times GearScout evaluation would ring true without an honest attempt to simulate some battlefield wear and tear. So like a pair of heterosexual males cast as fathers to an inanimate object, up to this point John and I lovingly saw our little "Leo" through the first stages of his life. Mounted, zeroed and calibrated, he was ready to be introduced to the real world. We tossed Leo, attached to my rifle, into the back of a bare metal pick-up truck bed and hauled ass across 50 miles of rural highways and dirt roads.

Leo emerged transformed. His young, anodized skin now bore the marks of teenage years. Like battlefield acne, a few scrapes and rub marks gave the optic some character -- but would it indicate some damage beneath the skin?

We set up steel targets at 100-meter intervals out to 600 meters. Working the turrets in fading light with a rangefinder and the BDC turret, we both rang each bell. Then we used reticle holds to go back over the targets. This involved some math as we had to work backward to true the 7.62mm reticle to give us good dope with our 5.56mm rounds. Aside from a couple fliers at 600 meters, the Mark 6 stayed true.

Then we decided to make it less boring.

John dropped the unloaded rifle upside down from chest high onto hard, packed earth. It landed with more of a bang than a thud. Picking the rifle up, I could see a bright mark on the elevation dial where it made first contact with the ground. There was also a little earth inside one of the turret locking screws.

Back on the firing line, we put a three-shot group into the 100-meter paper. Uh oh. It was about 20 cm low and 10 cm right. Crap. Did I just buy a broken $2,000 optic? John and I quickly went through all the emotional stages of a gear test gone wrong: cursing, blame, redirection, blame, dejection, acceptance, conference, supposition. Then we checked the mount.

Sure enough, the mount had moved. It was still quite tight, but it had a tiny bit of play that we could feel and then see as we pushed the mount fore and aft on the rail.

On the initial install, I had followed LaRue's instructions and tightened the bolts so the levers began engaging the rail at about 40 degrees. Screw that. We pulled out the wrench and cranked lever bolts down until all movement was gone from the system. It took about about 2+ full turns to get the play out of the mount.

We re-zeroed the rifle and were off and running. The Mark 6 and the LaRue held zero through the next 2,600 rounds that included another three-foot drop test and a 24-hour salt water submersion test.

[singlepic id=4658 w=320 h=240 float=yes]The capless turrets are sealed with O-rings, so there are no caps to unscrew before adjustments are made. Handy. There is a downside to Leupold's O-ring design. They use larger, more compressed O-rings that make the turret clicks feel a little squishy when compared to some other scopes. Leupold's stance is they'd rather sacrifice a bit of feel to make certain the optic will perform under the most hard conditions imaginable. But they are sensitive to this issue and tell me that they have been working to get a snappier feel and will continue to tweak their knob design.

Durability recap: The scope took an hour ride sliding around the back of a metal pickup truck bed, two waist-level drops while mounted on a rifle, 24 hours in a salt water tank. Result: No damage.

That's darn impressive for a device with a magnification erector and a set of reticle turrets that move on a screw with hundreds of threads per inch. This is essentially a supergrade photographic zoom lens. If you don't think this is impressive, go drop your own zoom lens and see how it does. I can tell you that even if it doesn't explode into a rainbow of plastic and glass, it will still never be the same lens again.

I touched on mushiness of the elevation and windage knobs already. Despite the feel, the knobs and lock are the perfect size to operate with or without gloves. The locks are set up so they just need to be pushed about halfway into the knob body to release the turret. Markings are clear and durable and even include R and L on the windage knobs to keep you and your spotter in sync.

[singlepic id=4663 w=320 h=240 float=yes]The BDC turret worked like a champ. As I mentioned earlier, we were dropping rounds on target with no problems. Running the Mark 6 with a rangefinder is a point-and-shoot affair with the right BDC scale on the turret. Leupold tells me their custom shop can make a BDC for just about any round you'd like. Just give them a call.

While we're twisting the turrets, let's talk about elevation adjustment. It's one of the weak points of the scope. It locks at zero and moves one full rotation in. This means you can only run the elevation up. This presents an annoyance in two situations: shooting with a suppressor and shooting at a higher elevation than your current zero. Neither of these apply to 3-gunners and hunters, but it does for guys that switch between suppressed and unsuppressed weapon operation or board aircraft with a weapon zeroed in one region and deplane (or jump from it) at a much higher elevation.

This is a pretty in-the-weeds function for an optic. I can forgive a sporting optic maker from including this feature, but one that is making strides -- huge, ball-dragging strides to get back into the tactical market? No. Leupold should consider setting up the lock so you get one or two mils down and take the difference off the top. This will set the scope up to deal with both military specific scenarios. An alternative -- but less effective -- fix is to add a hold-under feature on the reticle.

[singlepic id=4664 w=320 h=240 float=yes]The erector for the magnifier is a large, knurled surface that is easy to grab and twist. It's not stiff, but it won't move without an authoritative touch. There's a large tang that orients the 1x position at 12 o'clock so you can confirm your magnification setting without looking at the dial. There's no accommodation for a cattail. This was not an omission but a conscious decision by the optic's designer to ensure reliable operation of the magnifier. Spinning the tube with a cattail produces far more torque than twisting it with your hand, and Leupold has seen damage done to the magnification erector system as a result.

[singlepic id=4659 w=320 h=240 float=yes]The seven-level illumination control works and feels solid. Despite having off positions between every illumination setting, it could be improved with the addition of a lock in the off position. It's rare, darn rare, that the illuminator dial would turn under environmental interaction alone, but the world downrange is a rough place and strange things happen getting in and out of aircraft and vehicles. As a general rule, anything that emits light in a tactical environment should have a lockout. Aside from light discipline concerns, nobody likes dead batteries.

The Mark 6 will be offered in three flavors: TMR, CMR-W 5.56 and CMR-W 7.62, the reticle we've been using.

The Mark 6 is a front focal plane optic, meaning the reticle and target grow and shrink together as the zoom ring turns. This means the reticle markings are supposedly usable through the entire zoom scale, although the range markings are almost invisible against all but a solid-colored backdrop until you get to the 3.5x+ magnification range.

On the flip side, the lit circle dot is too small to use effectively at 1x magnification. The outcry in the shooting community for a true 1x optic was nearly deafening when the Mark8 1.1x8 came out. Ironically, it turns out that nobody actually uses these things at 1x. Sure, all the buzz about shooting with both eyes open at 1x sounds good, but in practice the reticle on an FFP optic is too small to be seen when used in the real world. Even lit up, the thing is still a 1 MOA dot, and most shooters will just crank the magnification up to 1.5x-2.5x for 0-25m CQB applications. They can still shoot with both eyes open, and they can see the aiming point. Used with a little magnification and illumination the dot is easy to see and the optic is, indeed, very fast.

Ideally, we'd see a red dot aiming point that moves in reverse of the magnification view, starting out large and growing smaller as the magnification rises. Sadly, that tech is out of reach for now, so we won't hold it against Leupold. But they are using some tech that is new to the rifle scope market in their reticle etching process called holographic grating. Traditional reticles are made by etching a glass lens and filling the etched area with titanium dioxide material that reflects the reticle image. Holographic grating is not new technology, but it is new to the optics market, and Leupold pioneered its use in the this space in the CQBSS.

As a result of using this new reticle etching process, the reticle displays some odd behavior when illuminated. The illuminator has an unforgivingly narrow field of presentation. Getting into shooting position, you'll find you can move a little left, right, up and down before you can't see out the other end of the optic. We'll call the space you have to move in before the tube goes black your eye box. At 1x, with the illuminator on, as you move around in the eye box, the illumination will to flare and dim as you move your head out of the dead center of the eye box.

Leupold has identified this issue as an artifact of the holographic grating reticle technology and has figured out that the angle that the LED sits at in the LED housing is far more critical to illuminator performance than they first realized. They are adjusting their manufacturing to address this issue.

[singlepic id=4707 w=320 h=240 float=yes] One other issue comes up when the illumination is cranked all the way up. The illuminator catches the edges of all the reticle markings and creates a subtle landing strip or Christmas tree effect when viewed against a dark backdrop. I don't know why you'd be cranking the brightness all the way up when using the optic in low light, so this is more of a PSA to keep you from freaking out should you buy one of these and notice this behavior.

The 34mm tube collects a lot of light and makes the Mark 6 usable in some pretty low-light conditions. Dusky shoots were no issue. In fact, we shot steel and paper lit up with a set of truck high beams well after dark to see what we could get away with. Turning the optic into a point light source like a headlight or revealed no strong haloing or inner reflections.

[singlepic id=4662 w=320 h=240 float=yes]Sharpness and resolution were impressive, even at the edges of the lens. The Mark 6 will not be to blame for target identification issues. We saw no evidence of internal fogging after freezing and thawing the scope. We found the internals were clean and dust free.

Durability and waterproofing
Fast and easy to use
Smooth operation
Packs a lot of performance into a small package
Fabulously clear glass
Common 34mm tube size
4 inches of eye relief
Sub-$2,000 price

Unforgiving eye box illumination* (addressed in production)
Reticle undersized for use at 1x magnification
Circle-dot aiming requires shooter to come on distant targets from above, which feels awkward
Turret clicks could be more positive
Elevation locks at zero with no easy way to hold-under

[singlepic id=4666 w=320 h=240 float=yes]The American-made Mark 6 is a fine optic that fills a gap in the market for short- to mid-range shooters looking for premium quality at a reasonable price. For your money, you'll get an unquestionably rugged rifle scope that will grin when faced with combat conditions and laugh through a summer of 3-gun events. The Mark 6 maintained its accuracy despite our efforts to break and drown it. With 4 inches of eye relief, the optic is comfortable and fast to shoot, and its shortcomings pale in comparison to its performance on the range. The Mark 6 is in production now and should be on store shelves by late June, early July.

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LEUPOLD Mark 6 Specs:
1-6x20mm RIFLESCOPE     
Reticle & Item Number:
    CMR-W 7.62 114337
    CMR-W 5.56 115044
    TMR 115045
Lens Coating:    Xtended Twilight Lens System with Diamond Coat 2
Adjustment Markings:  Zerolock 0.2Mil per click
Maintube Diameter: 34mm
Special Features:
    Superior 6:1 zoom optical system
    Illuminated Front Focal Plane Reticles
    Daylight Visible Illumination also Compatible with Night Vision
    Zerolock Adjustments With Available BDC
Environmental Protection:    2nd Generation Krypton / Argon, Waterproof, Fog Proof
Eyepiece Design:    Locking Fast Focus
Actual Magnification:    1-6
Linear Field of View (ft @ 100yd):    105.8-19.3
Linear Field of View (m @ 100m):    35.2-6.4
Exit Pupil (mm):    10.2-3.3
Weight (ounces):    17.0
Weight (grams)    :    482
Length (in):    10.3
Length (cm):    26.2 Devices
Mounting Space (in):    5.0
Mounting Space (cm):    12.7
Objective Aperture (mm):    20
Eye Relief (in):    3.7
Eye Relief (mm):    94.0
Elevation Adjustment Range (MOA): 130
Windage Adjustment Range (MOA): 130