The FightLite Mission Configurable (MCR) is a belt-fed upper receiver assembly designed for use on AR-15, M16 and M4 rifles. The upper is available in semiautomatic or full-automatic configurations.

By Frank Iannamico


The FightLite/Ares Defense Mission Configurable Rifle (MCR®) is an updated and improved version of the Ares Shrike belt-fed upper receiver assembly for the M16/AR-15 platform, first introduced to the public around 2002. The MCR upper is designed to interchange with standard M16, AR-15 and M4 upper receiver assemblies and readily attaches to any MIL-Spec (small front pin) lower receiver without any permanent modifications.

The FightLite MCR is designed to use metallic M27 links for the military issued M249 light machine gun. The MCR upper receiver assembly is shipped with 100 links.

The MCR is based upon the older ARES-16 AMG-2™ that has been on the Military/Law Enforcement market for almost a decade and is an AR-based solution to the M249 SAW. Now in its 6th generation, FightLite has improved various components of the system to make the weapon much more durable for sustained full-automatic operation. Updates include: a heat-treated, steel-feed plate designed to reduce feed ramp wear from steel core 5.56mm cartridges; an enhanced breech bolt lug profile; reinforced charging handle assembly; a reconfigured feed roller housing; and a proprietary method of mitigating cook-off risk, while maintaining a select-fire, closed-bolt system of operation that is more accurate and user-friendly than standard open-bolt light machine guns (LMGs).


Some additional key elements of the MCR are that it shares a 52-percent part commonality with existing M16-M4 components. The MCR with the use of an adapter can utilize GI M249 SAW 100- and 200-round soft pouches and 200-round plastic boxes of linked ammunition. The FightLite MCR can also feed from standard M16-M4 magazines or a 100-round Beta C magazine if desired.


Things You May Need or Want


If you’re anticipating, or have already purchased, a FightLite MCR upper for your rifle, there are a number of accessories available that you may need to best utilize the MCR.

M27 Links


The link, cartridge, metallic belt, 5.56mm, M27 used for feeding the MCR is a metallic disintegrating link issued by the United States Armed Forces for use with the 5.56x45mm FN Minimi LMG / M249 Squad Automatic Weapon (SAW). Each link consists of a single piece of metal curved into two partial cylinders, into which adjacent rounds slide. The M27 link is a push-through design in which cartridges are fed by pushing them forward out of the link. With the round freed, the link is ejected. This is in contrast with older, non-disintegrating belt systems that were typically made of fabric and were fed straight through the weapon intact. The M27 links can be collected and reused. The links are considered expendable by the military.


The MCR belt-fed upper uses U.S. M27 disintegrating links, which means, unlike a belt, when cycled the links don’t stay together. They fall to the ground and can be hard to find unless you use a tarp to catch them. A magnet with a long handle will save you a lot of time and effort looking for and picking up links. The chances are good that over time, links are going to be lost; it is suggested that lots of them be procured.


The MCR is designed to feed from linked belts that are carried and normally fed from soft pack pouches: magazine, cartridge, 5.56mm, 100rd, (NSN 1005013341507 / NIIN 013341507) or the magazine, cartridge, 5.56mm, 200rd, “Soft Pack” NSN 1005015605162 / NIIN 015605162. Both were designed for the M249-Series Machine Gun. Although the official nomenclature is “soft pack,” they are better known by the euphemism “nut sack.”

U.S. military soft packs are used to store and feed the linked belts of ammunition. Shown here are the 100-round packs in ACU and Woodland camo patterns.

The soft packs are available in several camo patterns including Army ACU Digital, Woodland Camo and Coyote Brown. Hard plastic black or green boxes also designed for the M249-Series Machine Gun are also available.


Soft Pack Adapter


To attach the soft pack or hard plastic boxes to the FightLite MCR, you will need an adapter that fits into the host rifle’s magazine well and is retained by the magazine catch. The black anodized aluminum adapter permits mounting of GI M249 soft packs and plastic boxes of linked ammo to the weapon. The adapters are available from FightLite Industries.

Soft packs are also available for holding 200 rounds of linked 5.56mm ammunition; however, the pouches are just a container. The MCR can be fed belts without them.

In addition to the soft packs, GI hard plastic boxes are available. They have a 200-round capacity.

To attach the soft packs or plastic ammunition boxes to the MCR, an adapter is required. The adapter slides into the AR-15 / M16 magazine well and is secured by the magazine catch.

If you desire to operate the MCR from a stable tripod, KNS Precision sells an adapter designed to attach from a Picatinny rail to a standard .30 caliber or an M60 pintle.

At a cyclic rate of approximately 800 rounds per minute, barrels can overheat in a short period of time. Spare barrels are available in several different lengths. A non-contact infrared thermometer is a handy tool to monitor barrel temperatures.



There are a substantial number of bipods available for attaching to the MCR’s handguard available from TangoDown, Harris, Magpul and others. The one attached to the rifle in the photographs accompanying this article is from Magpul. When considering a bipod, be sure it will fit the MCR’s handguard that features a 1913 Picatinny rail.


Tripod Adapter

For a stable firing platform, the KNS adapter attaches to the MCR’s Picatinny rail and to GI pintles.

At an unloaded weight of 7.5 pounds, the MCR is relatively light for a high-volume, belt-fed weapon. For the most accurate, sustained long-range shooting, use of a stable platform such as a tripod is required. There are adapters for tripod use available from KNS Precision that are designed to attach from a Picatinny rail to a standard .30 caliber GI pintle or M60 gooseneck. The adapters are CNC-machined from 7075 aluminum with black anodized finish.

The KNS adapter on a GI M2 tripod. In this setup, there is no room for the soft packs or plastic ammunition boxes. No problem, the MCR can be fed belted 5.56mm ammo without a soft pack or plastic link box.



The MCR comes with a proprietary recoil spring, which is longer in length than a standard M16 spring. Reliable operation may require a heavier than standard 3.0-ounce CAR buffer. A standard buffer has three steel weights. The H buffer has one tungsten and two steel weights and weighs 3.8 ounces; the H2 buffer has one steel and two tungsten weights and weighs 4.6 ounces; the H3 buffer has three tungsten weights and weighs 5.4 ounces.


Spare Barrels


If you purchase an MCR belt-fed upper for your select-fire M16 or M4 rifle, one might assume that you are probably regularly going to perform 100- or 200-round, full-auto mag “dumps” more often than using the semiauto feature of your weapon. With a full-auto cyclic rate of approximately 800 rounds per minute, a barrel can be overheated in a short period, to the point of being dangerous. Fortunately, the MCR is designed with a quick-change barrel feature, which includes an integral insulated handle to easily change out a hot barrel. Instead of loitering around waiting for the barrel to cool down, you may want to consider a spare barrel or two. Spare barrels are available in 20-inch, 16.25-inch or 12.5-inch lengths. A handheld, infrared, non-contact thermometer is a handy tool to monitor barrel temperatures to avoid overheating and preventing dangerous cartridge cook-offs.


To save time and fingers, a linker for loading the M27 links is available from Kendall Ordnance.

The M27 links can be loaded by hand but linking several 100- or 200-round belts can be time-consuming, labor-intensive and hard on the fingers. Fortunately, a linker for loading M27 links is available from Kendall Ordnance. The linker is well made from high-grade, durable 6061 T6 aluminum. Key steel components are parkerized; cartridge guides are heat-treated spring steel. After placing cartridges and links on the loader, 25 rounds can be linked with a pull of the handle. The loader weighs 15 pounds and can be attached onto a board or table.

The MCR on an M16 rifle fitted with a Magpul bipod and a GI 200-round plastic ammunition box.