By Brad Meyers
Throughout the many years it has been in use, the MK-19, 40mm Grenade Launcher has gained a fine reputation as one of the most devastating weapons in our arsenal. This specially designed, fully automatic grenade launcher can fire multiple high explosive grenade rounds accurately out to targets further than 2000 meters as long as there is sufficient light to see the target. At night, however, it used to be practically blind since no effective night vision sighting system was available for this high angle trajectory weapon, that is until now.
As a manufacturer of specialized night vision and laser systems for targeting and illumination, we took on the challenge of developing a high angle multi-purpose sighting system that would adapt to not only the MK-19 grenade launcher but also the .50 caliber HBMG. To mount either system, the US military has developed a weapon cradle that allows both the MK-19 and the .50 caliber HBMG to be alternately used in it. The cradle allows ammunition carriers and other equipment to be mounted directly to it. This makes the system completely transportable from tripod to mobile mount whether its on a tank, Humvee, or any other type of military vehicle. The first version of this cradle to be issued was the MK-64. A newer version with a buffer system is now replacing the MK-64 in some units and it’s called the MK-93. Both cradles are designed to be used for both the MK-19 40mm grenade launcher and the .50 caliber machine gun.
To manufacture a sighting system for these crew served weapons, we began a 2 year program and produced a series of prototypes that were tested by military groups at Fort Bragg, Fort Lewis and Fort Benning. Like all new systems, our original ideas, although they appeared to be effective, turned out to be not as efficient as we hoped. Through trial and error, we were able to refine this new sight which we now call the “MK Ranger” into an effective day/night sighting system that can guarantee “First Round Hits” in the “Dead of night. Multi-hit accuracy can now range out to the near limits of the weapon. This night accuracy is accomplished using 2 lasers, one to illuminate the field of view (IZLID-200) and the other to pinpoint the impact of the round (IZLID-100). The lasers are totally infrared and therefore invisible to the naked eye but very visible to 3rd generation night vision goggles. With the use of night vision goggles, the firer need not crouch down in an attempt to aim the weapon but simply use his night vision goggles to locate and pinpoint the target with the combination of illumination and targeting “hot dot” which can be made to be steady or pulsed. These illumination and targeting lasers can be easily seen with night vision goggles with their standard objective lens which is a 1:1, however, for ranges beyond 1000 meters, we recommend using a 3x or 5x lens adapter for the night vision goggles. This gives the firer a magnified view and lets him precisely put the dot on the target at extreme ranges. One unique feature of this system is that the illumination and targeting lasers are connected to the MK-64 or MK-93 cradle that mounts the weapon rather than to the weapon itself. If the weapon malfunctions, the weapon can be easily replaced with another and through a simple but highly effective bore sighting technique, an unfired weapon can be re-zeroed in a few minutes. This re-zeroing technique utilizes a mandrel or metal cylindrical which houses a pre-centered visible red, low power laser. By setting the range scale of the “MK Ranger” at 800 meters, one can line up the red visible laser from the bore of the weapon so that it illuminates the bore sight target cloth which is supplied with the weapon. This cloth target has a position on it for the red laser as well as a line up position for both the targeting infrared laser and illumination laser. This may sound complicated but its very simple.
Here’s the 3 easy steps:
Unwrap the range bore sight cloth and hang it from a tree or other area about 30 feet from the weapon. A piece of cord is included with our system that’s the right length. Insert the mandrel into the bore of the MK-19 and activate the red laser. Align the MK-19 or .50 caliber weapon so the red laser produced by the mandrel hits the targeted dot in the upper left-hand corner of the targeting cloth. If it’s dark, use your night vision goggles to adjust the targeting laser and the illumination laser so that it coincides with the marks on the targeting cloth. If this is being done in the daytime, be sure to use your night vision objective shields with a small pinhole in it so as not to damage the image intensifier tube. Each laser is equipped with a positioning device for vertical and horizontal beam adjustment. Adjust the clickstops on the laser until their targeting dots coincide perfectly with the dots on the targeting cloth. If the laser adjustment travel is not quite far enough, you may use the coarse adjustment built into the MK-19 laser mount. This will allow you to come within range so that the individual fine laser adjustments can now be used. Align both of these lasers with the corresponding alignment targets or crosshairs on the bore sighting cloth. This, of course, is done while your range setting is set at 800 meters. The range setting scale is illuminated with a blue-green illumination LED that will appear the same intensity to your naked eye or if you were using night vision goggles. Once bore sighted, that range scale can now be adjusted to maximum or minimum range and still hold accuracy.
Activation of the lasers is controlled from a pressure pad that is Velcro mounted to the spade grip. By pressing the top part of the grip the targeting “hot dot” is activated, by pressing the bottom part of the spade grip, the illumination laser is activated and by squeezing the entire spade grip, both are activated at the same time. Both laser systems are zoomable, that is, the dot may be reduced to a fine pinpoint or to a broad illumination field, simply by turning the front lens, the illumination laser which is twice the power of the targeting laser, can be used to illuminate a vast area and can clearly pinpoint one tank or vehicle from another. The lasers contain their own batteries and operate for more than 6 hours on their “AA” and “C” cells. The entire system, including the lasers are waterproof to a depth of 66 feet (2 atmospheres).
During our initial development, we knew of only the MK-64 mounting cradle and originally designed the system exclusively for that mount. Later, we learned a new version, the MK-93 was rapidly replacing the MK-64 cradle. We imagine the MK-93 will eventually replace the MK-64 totally, but right now many groups continue to use the MK-64 while others prefer the MK-93. Both cradles are very usable but both have their special peculiarities. The MK-64, although an excellent cradle, has some excessive tolerances in it, particularly when used with the .50 caliber HBMG. Since our lasers are mounted to the cradle rather than to the weapon itself, we noticed that once sighted in and firing, the .50 caliber HBMG weapon would move many feet off target because of the excessive tolerances within the mount.
This problem was solved with an accurizing device which fits beneath the .50 caliber and actually pushes it to one side and locks it securely to the cradle. This accurizing device is easy to install in the field and insures “first round hits” while using the .50 caliber in the MK-64 cradle.
The MK-93 on the other hand, is an excellent cradle and has no excessive tolerances, however, because of its design, the .50 caliber link ejection port may cause links to jam up against the “MK Ranger” mount after a short time. A special link ejection tray was designed which solved the problem very effectively.
In the military manual, it suggests the MK-19 be locked down with the T & E (Transverse & Elevation Mechanism) and held rigidly when firing. Although this does work, we found that the weapon with a laser can actually be “free gunned”, thereby allowing the shooter to attack multiple targets, a technique that he was not able to do before. The MK Ranger system, beside utilizing our IZLID-100 and IZLID-200 lasers, has optional brackets available to allow it to use standard Aimpoint( type day sighting systems as well as other night vision devices such as the PVS-4, TVS-5, TWS thermal sight, and also includes optical rifle scopes via its built-in Picatinny Rail Mount.
HOW IT WORKS
Notice in the photograph, the range scale. This scale has pre-etched range numbers on it. These correspond to the ballistics for a particular type of munitions. A variety of range scales are included with the “MK Ranger” system and can be installed in a matter of a few seconds. Each range scale will allow the laser depression angle to click-stop through a variety of ranges from 0 to 1700 meters. With an optional add on feature to the “MK Ranger”, we can increase the range to well beyond the 2300 meters which is typically the maximum of the weapon.
For more information on the patent-applied-for “MK Ranger” high trajectory system or other patented infrared illumination systems, contact us through our web site, www.bemeyers.com.
|This article first appeared in Small Arms Review V2N9 (June 1999)|