Review: Leupold Mark 5HD M5C3 3.6-18x44 H59

The Leupold Mark 5HD 3.6-18×44 with M5C3 turret and FFP H59 reticle is a serious scope for true long-range target shooting, but could also be used for varmint sniping or serious stretch-out big-game hunting. The H59 reticle can match the ballistics of any modern magnum.

It is one of Leupold’s more interesting top-of-the-range rifle scopes — a long-range optic that is compact, unlike the majority which are oversized.

Review: Leupold Mark 5HD M5C3 3.6-18x44 H59 — We used the Leupold 3.6-18x44mm on a Gunwerks ClymR rifle for testing the accuracy of the .300 PRC

It weighs less than 740 grams (26 ounces), has a 35mm main tube, a width of 73mm (2⅞”) at the turrets, and the reasonable length of 30cm (12”).

Obviously, it is not a hunting scope, but the 53mm outer diameter of the objective-lens housing allows mounting the scope fairly low, so that its short length would position it perfectly on a rifle carried by a hunter.

A deer stalker who thinks he can use the extra magnification will find it in easy reach.

This 3.6-18x44mm scope was built with input from elite-level military personal and professional long-range shooters, and Leupold pushed the engineering levels.

One feature is an elevation dial which has three revolutions of adjustment to max out the performance of the latest long-range rifles. Ergonomically designed, it has more tactile, audible click adjustments and larger numbers so you can put accurate fire down range faster.

On the left of the mechanism block is a side-focus knob for adjusting parallax with seven yardage graduations from 75yd to infinity, which allows you to quickly and easily focus the scope’s image to eliminate parallax.

The larger main tube allows room for more travel of the erector tube suspended within it, which means a greater adjustment range. The Mark 5HD has an elevation adjustment range of 29 mils (100 MOA) and a windage range of 23 mils (80 MOA). A large adjustment range is necessary for truly long-range work.

The elevation and windage dials include 0.1 milliradians (or mil) per click. That is 1cm at 100m, 2cm at 200, 4cm at 400, etc; or .36” at 100yd etc. After sighting in, the adjustments can be returned to zero by Leupold’s new M5C3 ZeroLock turret.

The elevation dial contains a lock release button located on the top side of the dial. The dial locks in the zero position but can be unlocked by pressing the button and turning the dial one or two clicks to raise elevation. The dial can also be turned five clicks below zero to sight in at a shorter distance.

To indicate where the dial is set, the button remains extended during the first revolution; pulls in flush with the dial during the second revolution; and on the third revolution, the button pulls inside the dial and a silver indicator pin protrudes from the top of the dial. Each turn covers 10 mils.

The Mark 5HD scope’s 0.1 milliradian adjustments mesh with the FFP H59 reticle, which was designed by Horus Vision. The grid-style reticle looks complicated but is actually very intuitive and easy to use. Instead of dialling you simply hold.

For this purpose the H59 uses hash marks (instead of the more common dots) on the horizontal and vertical wires. The H59 hash marks are spaced at 0.5-mil intervals for the first four mils and then transition to 0.22 mil between the fifth and sixth spacing, with intermediate fine lines in between which are 0.1 mils apart.

The Horus reticle’s most obvious virtue is that it’s etched onto glass and there is nothing to move or break. There are no clicks to count and forget, and it is exponentially faster than turrets when it comes to making that first shot or following up with a correction.

Another advantage: it’s located in the first focal plane where the graduations are accurate at any power setting.

Power changes are made by turning the ring located just forward of the ocular lens housing. A threaded and removable throw lever gives the user added leverage, a useful feature when making adjustments from field positions.

With magnification adjusted to 18x, 10 mil of hashmarks are visible. The scope’s hash mark spacing has centralised dots at crosshair intersection marking every 0.1 mil, providing refined aiming marks for bullet drop compensation and wind correction. Multiple points provide excellent corrections for follow-up shot placement while numbered lines make for quick line identification. The open half of the reticle is useful for observation and spotting.

On powers below 8x it is difficult to see the hash marks and to distinguish the space between them. The reticle works best used as just plain crosshairs when set on the lower powers.

The Mark 5HD was mounted in medium height 35mm rings made by Porter Machine Works attached to a Gunwerks ClymR rifle in .300 PRC. The scope made it easy to sight-in and test the rifle, and it did not shift its zero. Leupold’s Twin Bias Spring Erector System, which utilises leaf springs, has increased erector holding force by 30 percent over single-spring systems.

Clicks are positive and, more importantly, accurate and repeatable. We confirmed this by ‘shooting the square’, firing a shot and then dialling either one mil of elevation or windage before firing a subsequent shot and repeating that step in a clockwise direction, finally returning to centre. This ensured that the scope’s internal mechanism tracked accurately and repeatably.

The temperature was barely 6°C on the morning we shot the ClymR with the Mark 5HD, but a blue sky and bright sunlight made conditions bearable. I pinned a resolution test chart in dark shade next to the target at 100yd. With the scope set on 18x I could easily distinguish the largest set of bars in the fourth-smallest cluster of bars.

The Mark 5HD has an exit pupil of only 2.44mm at 18x. Still, that is a usable amount of light in most conditions. I expanded the exit pupil to 4.4mm by cranking the power down to 10x which enabled me to differentiate three smaller sets of bars. Moving my head left to right and up and down, those sets of bars were still distinct.

Magnification covers a broad spectrum of uses by running from 3.6x all the way up to 18x. Despite the five-fold change, eye relief remains the same — a non-critical length of about 90-100mm (3½-4”).

Objective lens diameter is a reasonable 44mm. Lenses are all multi-coated for superior light transmission and a sharp image. Diamond Coat 2 scratch-resistant lens coatings protect outer lens surfaces.

Optically, the 5HD resembles an up-market European scope. Leupold claims its Twilight Max HD light management system results in superior edge-to-edge clarity, increased low-light performance and increased contrast. Indeed, I was impressed by its excellent and very neutral colour rendition. The image was sharp and clear with excellent resolution and contrast.

No curvature of the field, pin cushion, barrel distortion or rolling distortion was detected. The acuity of the 5HD was really impressive. The most minute details were readily apparent while looking at pine needles and gum leaves 100-plus metres away. It is to Leupold’s credit that the image quality at 18x is extremely good.

This Leupold is a really high-tech optic, but given its price tag of around $4000 or more, it isn’t within the budget of most shooters. Those who can afford it can be sure they are getting the best of what Leupold has to offer.

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