L-3 Communication’s new Articulating Rail System for the M240 machine gun may be the coolest thing I’ve seen (that I can write about) at Modern Day Marine 2012. L3 started development on the pivoting optic mounting system about 2.5 years ago in an effort to prevent guys from having to swap out heavy machine gun optics for day and night missions.

L-3 stressed that the system makes no alterations to the machine gun, whatsoever. The ARS is a drop in rail system that sits atop the feed tray cover rail on an M240. The rail is long enough to accommodate a pair of optics, shown here with a Trijicon SU-260/P and a new PAS13 thermal. If you look closely, you can see L-3 reached out to LaRue for some help with the mounting levers.

Now, the trick is being able to manipulate the weapon as if there wasn’t a big optic getting in the way when the gunner flips the feed tray cover up. The forward end of the rail automatically flips over to the side when the feed tray is lifted. The machine gunner simply loads the next belt, closes the cover and snaps the thermal/I² optic back over into place. No drama.

The two challenges faced by the engineers making the ARS were making a system that could withstand the weight of the secondary optic when it snaps out of the way during the feed tray lift and making sure the system could withstand the punishing recoil of the M240.

Another, separate, part L3 developed to help gunners is the feed tray cover actuator. With a beefy day optic sitting atop the machine gun, the pinch levers are tough to reach. The new actuator is a drop in part that opens the feed tray with a push of the thumb on the left side of the gun. Check out the video below.