The LWRCI: International M6 Individual Carbine

By Christopher R. Bartocci

Anyone who has been keeping up with the status of U.S. military small arms over the past 10 years or so has seen a concerted effort to replace the seemingly aging and outdated M16/M4-series rifles. While evidence shows clearly that these weapons are as efficient today as they were when they were introduced in the early 1960s and have served well throughout the intervening years the question remains, can we do better? Or have we basically hit a plateau in development of weapons that fire the metallic cartridge. Perhaps the next leap of technology will be the introduction and acceptance of another form of ammunition such as caseless ammunition.

Without delving into the controversies leading up to the Individual Carbine competition, it is suffice to say that the Army was forced into holding an open competition to the industry to see if there is a rifle out there that is superior to the existing M16/M4 series rifles. This is to ensure the American soldier does in fact have the best weapon available to them. Many seem to feel the Army is running these trials only to get congress off its back and that they already are of the opinion the M16/M4 weapon is the best for the U.S. military, regardless of the outcome of the trials. The possibility of a successor to the current weapon would be based on if the weapon displays a “significant leap in technology.” This is a very open ended statement. Of course you have to consider cost, parts compatibility, training and so forth, which really raises the bar on a new weapon taking that term. Many companies submitted rifles for testing including FN USA, H&K, Remington, Colt, LMT and ADCOR Defense to name just a few. LWRCI developed a carbine based on the requirement, but did not submit its candidate at the last minute. They analyzed the bureaucratic hurdles in the requirement that would have cost millions of dollars to overcome with little chance of the Army actually procuring a new carbine.

They opted out.

LWRCI, International is not new to the small arms business. In fact, they may well predate H&K with the development of putting a short stroke piston operating system in an M4. Tracing the short stroke tappet operating system goes back to 1968 with the Winchester conversion system for the M16A1, then the 1980s with the RHINO system followed by H&K and LWRC. LWRCI has far more than a decade of development and refinement to their proven design. LWRCI submitted a very innovative design of their system to the Infantry Automatic Rifle competition of the Marine Corps. They have been actively perusing law enforcement contracts and now have entered the international military market scoring the first ever large scale military sale of a PDW chambered for the 6.8mm SPC cartridge. This is a monumental accomplishment in the history of the caliber. LWRCI would have liked to enter the Individual Carbine competition W15QKN-11-R-F003 in hopes to taking home the gold to become the next U.S. service rifle. The politics and bureaucracy of a big Army procurement prevented them from doing so, but they are offering their IC (Individual Carbine) commercially, to law enforcement, and the export market.

The LWRCI M6IC they designed as their contender for the competition focused on the advantages of improving on the durability, reliability and capability of the legacy M4 while maintaining the handling familiarization, and the manual of arms that the soldiers are used to. The M6IC utilizes a short stroke tappet piston system that does not introduce gases into the bolt carrier group as well as keeps the working parts running cooler not burning off or varnishing lubricants. It is also thought that in the absence of drastic heating and cooling cycles, there is an increase in the life of the bolt and bolt components, and definitely the springs. By not having this carbon and hot gasses introduced into the bolt mechanism, the maintenance on these components is significantly decreased.

The barrel of the M6IC is manufactured from 41V45 steel-alloy and the treated with NiCorr surface conversion technology. This process is deemed superior to using standard chrome plating. As per RFQ, the barrel is tan in color. The barrel is cold hammer forged 14.7 inches in length and fluted to increase strength and decrease weight. Rifled with the NATO standard 1 turn in 7 inch right hand twist and is capable of firing projectiles from 55 to 80 grains in weight. The barrel is capped with an AAC flash suppressor/sound suppressor mount. The barrel extension as well as the upper receiver has extended feed ramps on them. The gas block is held on by two taper pins to insure durability and contains a bayonet lug. There is a gas valve that has two positions. The first is for suppressed fire and the second is for non suppressed fire. There is a strip of Mil-Std 1913 on top of the front sight base where the detachable folding front sight is placed.

The upper receiver is modified as well. Featuring a forward assist assembly and a fired cartridge case deflector, the front portion of the forging is extended forward into the rail system for further durability. The top of the receiver is Mil-Std 1913 rail and the top of the handguard is removable to gain access to the piston mechanism for maintenance. However, once the top handguard is reinstalled, it is a complete return to zero. The top handguard is held in place by two pusher screws.

When the top handguard is removed, pull rearward on the intermediate rod while holding the piston cup forward and remove the intermediate rod. Now slide the piston cup off of the spigot. Pull forward on the operating rod assembly by pulling the assembly forward out of the upper receiver.

The charging handle is ambidextrous and used with no modifications for the individual shooter. There are two charging handle latches; the one on the right side actuates the one on the left to disengage the latch hook from the notch in the upper receiver. LWRCI beefed up the hardware on the charging handle using large axel pins instead of tiny roll pins as found on conventional designs.

The bolt carrier group has many improvements over the standard. The bolt carrier is one piece with the tombstone being machined into the top of the bolt carrier. This eliminates the key to break or the screws to snap off as seen on other rifles. The rear of the bolt carrier is fluted, which accomplishes two things: One it deals with and eliminates bolt carrier tilt caused by the off center movement of the bolt carrier caused by the operating rod striking the top of the tombstone and the second is with egression of dirt, fouling and whatever else may find its way into the mechanism. The carrier also has a proprietary nickel boron finish that creates a greaseless, permanently lubricious surface that is harder than the substrate itself and unlike chrome, conventional coatings, and applied lubricants; it never rubs off, thins out or builds up crud.

The Advanced Combat Bolt has many design changes over the current design. It sports a fully supported bolt face unlike the standard GI bolt. The extractor has been modified to a much stronger whale-tail extractor that utilizes two extractor springs instead of one. The face of the bolt has a crud groove cut around the perimeter of the inside of the bolt face. This permits brass shavings, primer sealant or any other residue a place to accumulate without being on the breech face where it may cause malfunctions. The bolt face fully supports the case head unlike the M4 bolt that has a large cut out for the extractor. This helps to prevent case head failures from high-pressure situations like shooting with water in the barrel. The geometry of lugs 1 and 7 has been redesigned to make these lugs much stronger and stress relieve preventing breakage.

The lower receiver has many modifications. First, the Magpul tan MOE CTR stock and MOE pistol grip are used. Also the Magpul enhanced trigger guard is used. On earlier prototypes of the IC, the Troy Industries ambidextrous magazine catch was used but LWRCI designed its own left side mag release. The LWRCI designed ambidextrous bolt catch is used as well. On the right side of the receiver, the familiar bolt catch is located within reach of the right handed shooter’s trigger finger and can easily be manipulated without unshouldering the rifle. This is a very efficient and reliable design. On the rear of the receiver on the back of the receiver extension is a provision to mount QD sling mounts on either right or left side. The selector is ambidextrous as well.

The M6IC is provided with tan PMags, which is probably the most reliable magazine in the industry for the AR platform of firearms. However, it is compatible with any NATO STANAG magazine including the H&K high reliability, GI aluminum, Lancer AWM, and so forth.

The cycle of operations of the LMRCI, International M6 Individual Carbine is as follows: when the trigger is pulled the hammer is released to strike the firing pin that strikes the primer. The spark is created by the primer, which ignites the propellant. Rapidly expanding gas is created by the burning of the propellant pushing the projectile down the barrel. As the projectile passes the gas port, gas is bled off of the barrel into the piston chamber located between the spigot and the piston cup. The piston cup along with the intermediate rod and operating rod move rearward; striking the tombstone on the bolt carrier driving the carrier rearward. The piston spring returns the piston components forward over the spigot. The cam pin rotates the bolt out of the locked and into the unlocked position and continues its rearward travel. As it moves rearward it extracts and ejects the cartridge case from the camber once it clears the ejection port. As the carrier group moves rearward it simultaneously cocks the hammer back and compresses the action spring and buffer. Now counter recoil occurs as the action spring and buffer return the bolt carrier group forwards. The bottom two lugs on the bolt strip the next round off of the magazine, chamber the round and the bolt carrier groups locks into the barrel extension. When the trigger is released the disconnector releases the hammer the trigger.

The M6IC is compatible with all current military ammunition ranging from 55 to 77 grains. The M6IC weighs 6 pounds, 7 ounces without magazine and sling and has an overall length of 33 inches with stock extended and 29.75 inches with the stock closed. The barrel is 14.7 inches with a 1 turn in 7 inch right hand twist and air cooled. The trigger pull is 5.05 to 8 pounds. With standard M855 ammunition, the M6IC has a muzzle velocity of 2,970 fps and a cyclic rate of 700 ±100 rpm.

The IC program is still in progress and its outcome is uncertain; regardless if something better is found or not. The question remains how much of an increase of performance does the rifle have to have for it to be considered a significant enough of a leap in technology to warrant a change. Some excellent rifles are out there that deserve to compete for the sake of the soldier. The M6IC is one of those excellent options. LWRCI is making available this year an M6IC for the commercial market, which of course will have a 16 inch barrel and be semiautomatic only. A limited number of tan rifles will be made and the rest will be manufactured in black. This author does intend on putting one of these in his collection.

This article first appeared in Small Arms Review V18N1 (February 2014)
and was posted online on November 15, 2013


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