When U.S. Army armorers uncrate the new rifle that was recently accepted as the XM-2010 and issue them to snipers in Afghanistan, Iraq, or whatever other combat zones might pop up in the very near future, the rifle will be equipped with an American designed and built optic that brings a lot to the table in terms of innovation and pure battlefield function. Officially it is known as the Mark 4
6.5-20X 50mm ER/T M5 Locking Adjustment Riflescope (M5A). Unofficially, it is the newly crowned king of a family of scopes that was pretty darn good in the first place.
Given the nature of our current conflicts–small-scale fights, low-intensity counter insurgency warfare–snipers play an invaluable role. A round fired by a sniper is the ultimate precision-guided weapon. The Remington M-24 was first fielded in 1988, chambered for 7.62x51mm NATO, and equipped with a fixed 10X Leupold scope. It served soldiers well. The Army originally specced long-action rifles in case they ever wanted to up the ante in terms of horsepower.
That day has come, and the rifle got a complete makeover from recoil pad to muzzle. The long action Remington now holds .300 Winchester Magnum cartridges, and it appears the Mk 248 Mod 1 round will be issued with the rifle. The cartridge seats a heavy 220-grain Sierra MatchKing HPBT that dramatically increases a sniper’s range since it remains supersonic out past 1,400 yards. The goal was to get snipers a rifle that worked well out to 1,500 meters. Current scopes did not have enough magnification, a fast or smart enough reticle, and–more importantly–the adjustment range to get the new .300 Win. Mag. round on target at extended ranges. So a solicitation was issued for not just a rifle, but a complete weapon system that included suppressor, stock, and new daylight optic.
That solicitation was the perfect challenge for Leupold Engineering Supervisor Steve Hodge and his talented team of mechanical and optical engineers at Leupold’s new Tactical Optics Division, which was formed to go after military contracts like this one. Given that the contract was for an indefinite period and indefinite quantity of optics–it will be the Army’s daylight sniper scope for some time to come–the solicitation attracted the attention of all the other big players in the business of building premium sniper scopes. Competition was stiff to say the least.
“We are actually a subcontractor on this one, since the solicitation was for a complete weapon system, but this was right up our alley,” Hodge said. “It’s a big deal to us since there have been a lot of foreign players in this arena in the past. Winning this contract would establish us as not only America’s premier optics manufacturer, but one of the best in the world.”
The resulting optic looks radically different from its predecessor, much the same way the XM-2010 compares to the old M-24. And just like the new rifle, it is infinitely more capable. The required adjustment range, 20 milliradians of elevation and windage, would require a bigger tube. The turrets had to get the reticle there in just two revolutions–that required bigger knobs. And most importantly, those turrets would have to automatically lock into place after an adjustment.
“We settled on a 34mm outside diameter since tube size was driven by the elevation adjustment requirement,” Hodge said. “That diameter allows the erector tube to tilt inside the scope body enough to get 20 mils.”
|Manufacturer:||Leupold & Stevens Inc., www.leupold.com|
|Model:||Mark 4 6.5-20X 50mm ER/T M5 Locking Adjustment Riflescope|
|Purpose:||Tactical, precision target|
|Eye Relief:||4.4-3.6 in./111-93mm|
|Field of View at 100m/100yds:||6.5X: 4.8 m/14.3 ft.; 20X: 1.8 m/5.5 ft.|
|Exit Pupil:||6.5X: 7.6mm; 20X: 2.5mm|
|Construction:||6000 series, heat-treated aluminum billet|
|Lenses:||Extended Twilight Lens System|
|Objective Lens Diamter:||50mm|
|Turrets:||0.1 milliradian adjustments|
|Turret Adjustment Range:||20 milliradians, windage and elevation|
|Rated:||Fog proof, waterproof, shockproof|
|Finish:||Type II black anodized|
|Weight:||30.9 oz./876 gm|
|Length:||36.8 cm/14.5 in.|
Most of the internal components are stock Mark 4 since the old design was overbuilt and easily passed durability and return-to-zero requirements. The one-piece tube is machined from a heat-treated billet of 6000-series aluminum and wears a Mil Type II anodized finish that is extremely durable. Due to the diameter, the outer walls are slightly thicker than other Mark 4 scopes. The erector tube is held in place by one, dual-bias beryllium copper spring. If the Army really likes the new Mark 4 and wants to pair with a .338 Lapua or .50 BMG, it is up to the task.
“We have a one-of-a-kind recoil testing capability here at Leupold,” Hodge said. “We gathered recoil signatures and then designed a computerized tester that matches those impulses. The Mark 4 scope got a thorough workout and is field proven on top of the M107 platform.”
Should the Navy take an interest or a paratrooper land in a lake instead of his drop zone, the scope is waterproof to 66 feet. Like most other scopes these days, the Mark 4 is nitrogen filled and sealed against the elements to prevent internal fogging.
The solicitation called for magnesium fluoride lens coatings, but Leupold already uses coatings that are several generations beyond that. The new M5A uses the standard but decidedly advanced Extended Twilight Lens System. It’s a series of vapor deposition coatings that provide exceptional light transmission across the entire light spectrum, especially at dusk and dawn. Hodge would not provide photopic transmission values since others in the optics game frequently misuse them, presenting just the most flattering readings of certain spectrum segments instead of providing an entire data set. Fair enough. I can tell you that the glass compares favorably to any other over-$3,000 riflescope on the market. Resolution and clarity are also excellent.
Another requirement was the Horus H-58 reticle. Those who do not understand how to use Horus reticles, and I was certainly in that group at one time, absolutely hate them and complain that they are busy and impossible to see. After a lot of practice, Horus reticles allow for extremely fast corrections and in some cases completely eliminate the need to touch a turret, especially if used in conjunction with a like-equipped spotting scope. In fact, the M5A scope does not have the typical windage adjustments, and covers that knob with the same kind of cap you would find on a hunting scope. The intricate grid requires placement in the first focal plane and an etched reticle (as does illumination), but the real trick was getting the H-58 to work perfectly and work perfectly every time with the M5A scope’s optical prescription.
“It took a lot of work to make that reticle function correctly from a design, engineering, and manufacturing standpoint,” Hodge said. “You don’t just call up Horus and order 200 reticles and stick them in a scope. We don’t use a canned optical prescription, rather our engineers take the reticle and design in features to make sure it works.”
During assembly, scopes are put in a collimator because each scope must be individually calibrated to the individual reticle. That way Leupold can guarantee the optic actually subtends a mil when it says it subtends a mil, at 20X or 13X or 8X.
The scope’s juice is in the patent-pending M5 locking turret. Hodge said Leupold had been tinkering with a locking turret for several years, but the solicitation kicked things into high gear. It still took six months to perfect a design. The M5 is locked in place, solid as a rock until the shooter presses in a small button on top and makes an adjustment. Releasing the button locks the thing in place again. It might not seem like a big deal, but at least a half-dozen times over the last few years I have witnessed shooters whiff a target because somewhere between here and there, their turrets were rotated inadvertently. The last time it happened to me, I sent six rounds downrange before realizing I had spun the windage turret two MOA off zero. It stank that I wasted six rounds, but that small mistake could get a sniper killed.
The locking mechanism is actually pretty simple, though it is completely different from the basic nut-and-screw arrangement found in standard Mark 4 turrets. A spring-loaded, hourglass-shaped spindle traverses the turret’s length. In the relaxed or locked position, the wide part of the hourglass spindle sits between paddles and forces them against an internal click ring. Pressing the button allows the paddles to fold against the spindle’s narrow end, allowing it to turn. Machined from aluminum, the turret body contains a bunch of parts made from a variety of materials. Hodge said the adjustments could be swapped from mils to MOA by swapping a half-dozen parts.
Zeroing the scope should present a pretty good picture of how both the zero stop collet and dial indicator function. For the scope and reticle to function properly, the reticle must be perfectly level. First loosen the three Allen-head screws on the elevation turret and then spin the turret down (clockwise) until it bottoms out. Then spin the turret back (counterclockwise/up) a half-turn to give it room for adjustment and tighten the Allen-head screws. Zero the rifle and then remove the elevation turret again. The slotted, zero stop collet should be screwed down against the scope body. Reattach the elevation turret, set to zero, and lock it in place with the three Allen-head screws.
The collet’s slots will catch a small tab that protrudes inward from the turret body. The tab runs the collet up and down the threads when adjustments are dialed. When the collet hits the base of the threads it stops, stopping the turret, and that is the zero stop. When the collet moves far enough up those threads it pushes a small stainless-steel pin up through the turret top and lets the shooter know he has made one complete turret rotation.
The Mark 4 laughed off all of my standard range tests, including shooting the square from hell, freezing, and being submerged in warm water for a few minutes. It was too pretty and too expensive to hit with a hammer.
So how do you and I get our hands on the exact same scope u
sed by Army snipers? Simple, call a Leupold dealer and order one, but it might take a while since all the units currently being produced are going straight to the field. And it is going to cost you. Base models have an MSRP of $3,875 but that is in line with other high-end, tactical scopes.
During a recent seminar where I was able to handle and shoot the XM-2010 and Remington’s Modular Sniper Rifle, company officials said they were still working out the details of exactly how the Mark 4 6.5-20X 50mm ER/T M5 Locking Adjustment Riflescope–wow, what a mouthful–would come to market. They envisioned a system where customers could order the unit with a specified reticle, custom BDC turrets with adjustments in mils or MOA, and even finish options through the custom shop. Since the reticle is etched, swapping out the Horus for a more standard pattern is pretty simple. Extras will cost, well, extra.
For the engineers, heck–for the guys who sweep the factory floors at Leupold, this new Mark 4 stands for something more than a government contract with a tidy profit margin.
“It validates what we’ve been doing here for a long time,” Hodge said. “We haven’t gone after the military market in the past, but the products are capable, the designs are robust and trouble free. This scope is built in the U.S. at competitive prices and is competitive with any other tactical scope in the world.”
End-users, read soldiers and Special Forces operators, helped write the solicitation and refine the Mark 4 until it was as close to perfect as Leupold could make it. So far, according to company officials, it has gotten rave reviews. You might not wear digital camo or MultiCam fatigues or get shot at for a living, but you can certainly take advantage of all the technology and extensive research and development that went into building this scope and use it to put bullets precisely on target early in the morning, late in the evening, in the rain or sleet or snow, cold or hot . . . well you get the picture, a very clear and bright picture.