LWRC M6A2-S Upper with MRE Finish - 5.56x45 NATO, 14.7" Barrel with Permanently Attached M16A2 Flash Suppressor (M6A2-S-MRE-5.56-14.7) $1920 This upper is no longer available.
	LWRC M6A2-S Upper with Black Finish - 5.56x45 NATO, 14.7" Barrel with Permanently Attached M16A2 Flash Suppressor (M6A2-S-BLK-5.56-14.7) $1920 The LWRC M6A2-S features LWRC's patented short-stroke, gas-piston operation in a true midlength configuration. The M6A2-S is not a standard item in the LWRC catalog and is made specially for Expedition Exchange by LWRC. This particular M6A2-S upper features the traditional black hard-anodized finish and is chambered in 5.56x45mm NATO. The hammer-forged barrel is 14.7" long and is free-floated within the midlength Picatinny forend with integral sling swivel sockets. The M16A2 flash suppressor is permanently affixed to the muzzle by the pin-and-weld method, extending the overall barrel length to longer than 16" and making this upper usable on non-NFA lowers. Troy Industries reserve iron sights, one-piece bolt carrier, and black rail covers are standard. H2 carbine buffer and carbine recoil spring are also included. To order, just call us.
	LWRC M6A2-S Upper with MRE Finish - 5.56x45 NATO, 16.1" Barrel (M6A2-S-BLK-5.56-16.1) $1920 This upper is no longer available.
	LWRC M6A2-S Upper with Black Finish - 5.56x45 NATO, 16.1" Barrel (M6A2-S-BLK-5.56-16.1) $1920 The LWRC M6A2-S features LWRC's patented short-stroke, gas-piston operation in a true midlength configuration. The M6A2-S is not a standard item in the LWRC catalog and is made specially for Expedition Exchange by LWRC. This particular M6A2-S upper features the traditional black hard-anodized finish and is chambered in 5.56x45mm NATO. The hammer-forged barrel is 16.1" long and is free-floated within the midlength Picatinny forend with integral sling swivel sockets. Troy Industries reserve iron sights, one-piece bolt carrier, and black rail covers are standard. H2 carbine buffer and carbine recoil spring are also included. To order, just call us.

 

LWRC International, LLC is headquartered in Cambridge, Maryland, utilizing three facilities totaling over 250,000 square feet. LWRC's manufacturing capability includes over 50 state-of-the-art CNC machine centers, laser-cutting machines, screw machines, robotic welding, plating, and mil-spec painting. LWRC is registered with Lloyd's Quality Registrar for ISO-9001 and AS9100 International Standards compliance for Configuration Management. LWRC's mission is to provide absolutely reliable, consistently accurate, and extremely durable small arms. LWRC's designers and engineers are not bound by the philosophy that mil-spec comes from God, and LWRC's weapons incorporate the latest design and manufacturing improvements not contemplated when the American Military came up with mil-specs. Through innovative design, disciplined engineering, and the use of state-of-the-art manufacturing processes and materials technologies, LWRC weapons represent the finest and most incrementally evolved AR weapons in existence.

LWRC was founded to pursue the development of a short-stroke, gas-piston operated version of the AR-15/M16/M4 family of weapons that eliminated the inherent disadvantages and shortcomings of these weapons' direct-impingement method of operation. (The AR family of weapons is superb in almost all respects other than its method of operation.) LWRC's efforts were successful on all counts and have resulted in LWRC's family of short-stroke, gas-piston operated rifles and carbines that retains the best aspects of the AR family of weapons, but improves upon the direct-impingement system method of operation by operating more cleanly, accurately, durably, and reliably. These LWRC weapons represent the next stage of the AR's improvement and evolution.

This animation illustrates how Eugene Stoner's direct-impingement method of operation works. When the cartridge is ignited, gas pressure causes the bullet to leave the case neck and accelerate down the bore. When the bullet passes the gas port, the same propellant gasses that propelled the bullet forward surge through the gas port, through the gas block, through the gas tube above the barrel, and into the bolt carrier. Gas pressure builds within between the bolt carrier and locked bolt head, and the bolt carrier is propelled rearward pneumatically. This rearward movement of the bolt carrier turns and unlocks the bolt head and pulls the bolt head rearward to extract and eject the empty case. During this rearward movement of the bolt carrier, the propellant gasses that caused the rearward propulsion of the bolt group are exhausted through vent holes in the side of the bolt carrier, through the ejection port, and into the atmosphere.

The direct-impingement system as originally designed by Eugene Stoner in the AR-15 can work quite well and has several very real benefits. First, the system is very slim and lightweight. The bolt group, gas tube, and receiver are considerably slimmer and lighter than the equivalent parts of other self-loading rifles and carbines that employ different methods of operation. Furthermore, the direct-impingement system is also very appealing from a designer's perspective. All of the operating parts are perfectly inline and concentric with the bore, and there are almost no bending forces exerted on the weapon during operation. As a consequence, the direct-impingement system offers excellent intrinsic accuracy as well as aesthetic appeal and light weight.

There are, however, several disadvantages with the direct-impingement system. Propellant gasses used to power the system are inherently hot and dirty. Anything inside the receiver is subjected to those hot and dirty propellant gasses. Lubricants inside the upper receiver are burned away by the hot gasses, creating even greater heat and exacerbating wear and probability of parts failure. Small components within the bolt head such as the gas rings, ejector, ejector spring, extractor, and extractor spring are subjected to heating cycles and can lose their temper or fail completely. Small components within the bolt carrier such as the key screws are subjected to great heat and tend to loosen, which causes a gas leak and makes the system operate unreliably. Even when the direct-impingement weapons are operating reliably, they require more maintenance, inspections, and scheduled parts replacements than other weapons that operate on different methods of operation.

The shortcomings of direct-impingement operation are generally tolerable on rifle-length weapons such as the M16. These shortcomings, however, are exacerbated greatly on shorter weapons like the M4. As the AR family of weapons developed over time, its users shortened the barrels and gas systems to make the weapons lighter in weight and handier to use in confined areas. As the barrels and gas systems were shortened from Eugene Stoner's original design, much was lost. When the gas port moved closer to the chamber, the propellant gasses surging through the gas port and bolt group became hotter than previously, and there were greater amounts of unburned propellant going through the system than Eugene Stoner designed the system to handle. Dwell time also decreased substantially from Eugene Stoner's original design parameters. Extraction became less reliable because the bolt group was propelled rearward sooner and faster than originally designed by Eugene Stoner, and the bolt head extracted the empty case where there was still substantial gas pressure within it and the case was still adhered to the firing chamber. Gas port erosion also accelerated well beyond what Eugene Stoner had designed the system to handle. As the shorter weapon wears and the gas port erodes, the deficiencies become greater still and the already-faster rate of wear accelerates. As a consequence, shorter ARs like the M4 are generally less reliable than the AR-15/M16 and require even greater maintenance by the user to maintain an acceptable level of reliability.

LWRC has engineered a complete solution to the disadvantages found in the direct impingement AR-15/M16/M4 family of battle carbines. The principal improvement comes from the incorporation of LWRC's patented self-regulating, short-stroke gas-piston system. LWRC's system completely eliminates the venting of hot, carbon-laden gases into the receiver and bolt group, thus eliminating the intensive cleaning regime and short component life of direct-impingement battle carbines. In addition, the LWRC system offers improved handling characteristics over that of direct-impingement weapons. Perceived recoil is lighter and muzzle rise is reduced. Amazingly, LWRC accomplished all of these improvements in a weapon that is ergonomically identical to, weighs almost the same as, and retains 80% parts commonality with the direct-impingement battle carbine.

The innovative LWRC system is different from any other gas-piston system on the market. Most gas-piston designs utilize a fixed cylinder in the gas block and a reciprocating piston.

In contrast, the LWRC system utilizes a fixed piston (the "nozzle" in LWRC parlance),

and a reciprocating cylinder (the "piston cup") that slides over the nozzle. This arrangement has several advantages over other gas-piston designs. Because the LWRC system is very lightweight, there are no adverse effects on barrel harmonics and minimal downward-bending forces on the barrel during operation. The bolt group is no heavier than it is on the direct-impingement design, so the shooter does not have to deal with a heavy bolt group reciprocating within the weapon. As a consequence, the LWRC system offers greater intrinsic and practical accuracy than other gas-piston designs.

The LWRC piston system integrates a staged venting of propellant gasses. The LWRC system does not vent supersonic gasses in one violent dump. Rather, the LWRC system vents progressively greater amounts of subsonic gasses as the piston cup moves to the rear, with a final dump of low-pressure gas as the piston cup's vent holes move rearward past the tip of the nozzle. This controlled acceleration of the piston and operating rod accomplishes several things. The acceleration of the bolt group rearward is controlled and prevents the extractor from tearing through the rim of the empty case inside the chamber. There is less perceived recoil transmitted to the shooter. The minimal amount of propellant gasses flowing through the gas port and gas block also minimizes gas port erosion to minimal levels.

The controlled venting of propellant gasses also prevents injury to the shooter. The shooter can place his hand directly over the gas system with no risk of burn or injury. All he feels is a puff of warm gas. John shoots his personal LWRC weapons with his left thumb on the top-front corner of the port-side rail cover and uses that corner as an index for the placement of his support hand on the forend. His thumb is right beside the exhaust vents on the piston cup. But John has never been burned. In fact, John doesn't even feel the venting. He can feel the heat radiating from the barrel and gas block from extended firing, but he doesn't even feel any venting happening with each shot.

The LWRC system is very clean and requires almost no maintenance. The piston cup's hole is blind and carbon never makes its way past the rear wall of the piston cup. The carbon is merely vented into the forend. The nozzle is cut with sharp transverse ribs that scrape the inside of the piston cup with each round fired. The scraped carbon is loosened and blows out of the piston cup with each subsequent shot. LWRC's recommended cleaning interval for the piston is every 2,500 rounds, but we believe the system will go several times longer than that without user maintenance of any kind.

Because carbon never makes its way into the weapon's action, the weapon stays extremely clean. The photo above shows a receiver that was fired 150 times. You can hardly tell the weapon has been fired.

Here are the unique LWRC operating components. From right to left are the piston cup, the intermediate rod, and the operating rod. The components are designed so that they cannot be assembled incorrectly. All of the LWRC operating parts are grooved to facilitate disassembly and user maintenance. The LWRC system is easily the most elegant of the various gas-piston designs for the AR. When propellant gasses push rearward on the piston cup, the piston cup moves rearward and pushes the intermediate rod and operating rod rearward to propel the bolt carrier rearward to turn and unlock the action. While these components appear relatively simple, they have built-in features to create redundancy and increase weapon reliability in severe conditions.

Here is the piston cup. Note how thin the walls of the piston cup are. The minimal weight of the piston cup minimizes adverse effects on barrel harmonics and intrinsic accuracy. There are three exhaust vents on the piston cup's walls, with one vent every 120 degrees. The exterior of the piston cup is grooved to facilitate disassembly of a severely fouled weapon, but it is nearly impossible for these vents to become clogged from even extreme use. Every time the piston cup reciprocates, the grooved nozzle scrapes the piston cup's interior walls and keeps the piston cup clean, smooth, and operating reliably.

Here is the LWRC operating rod. The operating rod assembly is composed of three different pieces: the operating rod, the operating rod spring, and the spring cup.

The operating rod is propelled forward by the operating rod spring. The operating rod spring has a stiff rate and the operating rod's front collar does not normally bottom against the spring cup during operation. After the operating rod propels the bolt carrier rearward, the operating rod spring pushes the operating rod, intermediate rod, and piston cup back into battery. Thus, the LWRC is properly categorized as a short-stroke piston design, because it travels less than the length of the cartridge. Long-stroke designs like the various Kalashnikovs have the piston fixed to the bolt group, and the piston travels the entire length of bolt group travel (which is necessarily longer than the cartridge length). The short-stroke design requires a greater number of components but has the advantage of a lighter mass of components reciprocating within the weapon during firing. The result is less perceived recoil to the shooter and greater control of the weapon during rapid fire.

The spring cup prevents the operating rod spring from deformation from compressing to solid during operation,

and also acts as a stop against the collar of the operating rod in the unlikely event the spring should fail. Even if the spring should fail, the system will continue to operate as the operating parts will be pushed forward into battery by the bolt group's going into battery within the upper receiver. The LWRC uses about 1mm of float in the operating parts. That is, the operating parts will move rearward approximately 1mm before the tip of the operating rod contacts the anvil on the bolt carrier. Even if the operating rod spring breaks or weakens or the piston cup is so fouled that the resistance is more than the operating rod spring can overcome, the bolt group's going into battery will push the operating parts back into battery. This level of redundancy does not exist on many of the other gas-piston conversions by other manufacturers. Many of these other designs rely solely on the proper function of the operating rod spring and will not function if that single component is not functioning properly.

The spring cup rests against the standard AR barrel nut. Not only is parts commonality with the standard AR maintained, but the barrel nut is prevented from loosening by installation of the operating rod. The operating rod rides within a steel bushing pressed into the upper receiver. The steel bushing prevents wear and tear to the aluminum upper receiver and also keeps the operating rod perfectly centered. The operating rod bushing is flanged and is sandwiched between the upper receiver and the barrel nut. The operating rod bushing will not move. Contrast LWRC's design with aftermarket gas-piston conversion kits which use a steel roll pin pressed into the upper receiver. These aftermarket conversion kits lack the engineering, redundancy, and reliability of the LWRC system.

Assembled, the operating parts look like this. Note how the nozzle is raised relative to the gas block to orient all of the operating parts in a straight line back into the receiver. There is no twisting or canting in the LWRC system. The LWRC system also low enough to permit the use of the standard AR upper receiver. Many other gas-piston designs like the Heckler & Koch 416 require a taller receiver to house the taller operating parts, which negates one of the advantages of Eugene Stoner's design (a very small and lightweight receiver). The taller piston axis on the HK416 also exerts greater downward bending forces on the barrel and exacerbates the probability of carrier tilt.

Here is a close-up of an assembled LWRC weapon. With the upper receiver height of a standard AR and not raised as on the HK416, the LWRC uppers will accept standard AR telescope mounts like this LaRue SPR-E without having the optical device being too high above the comb.

Relative to the bolt group, the operating parts look like this. When the bullet passes the gas port, propellant gasses flow through the gas port, through the gas block, and out of the nozzle. The propellant gasses push the piston cup rearward, which pushes the intermediate and operating rods rearward, which propels the bolt carrier rearward to turn and unlock the bolt head, extract the empty case, and eject it out of the weapon through the ejection port. When the piston cup has moved rearward a sufficient amount for the vents to clear the rear tip of the nozzle, excess propellant gasses are exhausted out of the vent holes in the sides of the piston cup. The carbon-laden and searing hot propellant gasses never make their way into the upper receiver or bolt group.

This animation shows the LWRC system in action. The animation shows the older, two-piece bolt carrier. LWRC now uses a one-piece carrier design with integral anvil. However, the unique method of operation remains unchanged.

The rear tip of the operating rod features a convex shape.

The convex point of the operating rod mates with a corresponding concave shape on the front of the bolt carrier's anvil. While the operating rod is a floating design, it is a floating design with several locations of centering. The operating rod is centered at its front by the intermediate rod. The operating is centered in its middle by the steel bushing pressed into the upper receiver. And the operating rod is centered at its rear by the anvil of the bolt carrier. The operating rod suffers no bending forces and is also prevented from bending from severe use by remaining centered in three different places. Many other gas-piston designs for the AR utilize a flat operating rod and anvil, which can lead to bending of the operating rod after heavy use. Not so on the LWRC.

The LWRC bolt group is as innovative as the method of operation.

And yet parts commonality with the standard AR is maintained. The carrier is not interchangeable, but the bolt head, extractor, extractor spring, extractor pin, ejector, ejector pin, ejector spring, gas rings, cam pin, firing pin, and cotter pin are fully interchangeable with standard AR pieces. And these smaller pieces are the ones that break with heavy use. Bolt carriers do not break. Accordingly, spare and replacement parts for the LWRC are very easy to obtain.

The bolt head is the standard AR bolt head, with gas rings. The gas rings are, of course, not required for the LWRC to operate. LWRC leaves the gas rings on the bolt head to facilitate putting the bolt group into the weapon and also to prevent the bolt group from falling out and hitting the charging handle when the upper is removed. If you like, you can remove the gas rings from your LWRC. Or you can leave the gas rings in place. It's your choice.

LWRC bolt carriers feature FailZero's EXO Technology. EXO is almost twice as hard as electroless nickel with teflon, and the lubricity is inherent in the EXO material rather than Teflon particulates mixed in with the plating material. EXO Technology is also one of the most corrosion-resistant and lubricious materials available in the firearms industry. And because there is no heat or carbon residue introduced to the bolt group on an LWRC, the bolt group will forever remain very easy to clean and maintain. The practice of scrubbing and scraping carbon from the bolt group and inside the receiver are gone. Simply wipe clean with an oily rag. FailZero claims that no lubrication is required for EXO-plated components. However, we always lubricate our personal weapons whatever they are coated with.

The LWRC carrier design looks vaguely like the AR carrier, but features numerous differences to suit the different method of operation and to maximize reliability in severe conditions.

The AR's gas key is replaced with a solid anvil to receive the mechanical hit from the operating rod. Repeatedly tightening and staking loose key screws in place is a thing of the past. The LWRC one-piece carrier replaces four different pieces with one.

Also note the faceted sides and the interrupted bearing surfaces. The faceted sides and interrupted bearing surfaces act as collection areas for debris and let LWRC weapons operate in the dirtiest and harshest of conditions. Note the lack of vent holes in the side of the bolt carrier.

Here is an LWRC upper during the ejection phase of operation. The bolt group has been propelled rearward and the empty case is just starting to tilt outward to eject. Note there is no venting of propellant gasses out of the starboard side of the bolt carrier.

The vent holes in the dust cover relief cut are gone, as they are no longer required. There is no more whiff of propellant in your face with every shot fired. However, LWRC wisely kept the vent hole for the bolt head's centering peg in place. Why?

Savvy AR users know how to lubricate the bolt group without disassembling the weapon. The four bearing surfaces of the bolt carrier, the anvil, the bearing surface between the bolt head's body and the carrier, the front of the firing pin, the extractor, ejector, and the locking lugs may all be lubricated perfectly well without disassembling the weapon. The only part that really cannot be lubricated though the ejection port is the bolt head's centering peg and the rear of the firing pin. Leaving the centering peg's vent hole permits such lubrication. Just place a drop of oil inside the vent hole with the weapon in battery and the centering peg will be lubricated. Pull back on the charging handle a little and put another drop inside the same vent hole and the rear of the firing pin will be lubricated. Removing the other vent holes but leaving the center peg's vent hole in place is a very thoughtful touch.

The underside of the carrier is very smooth to facilitate smooth operation. You have probably seen some high-dollar ARs with bolt carriers that are polished in this area. The idea is to smooth the bolt carrier in this area so that the carrier will ride more smoothly over the topmost round in the magazine (which is spring-loaded up against the bottom of the carrier). The LWRC bolt carrier needs no such additional clean-up in this area because the entire carrier is tumble-finished and very smooth. Also note the shrouded firing pin for smoother operation. Many ARs have exposed firing pin flanges.

The tail end of the carrier is swelled and tapered to prevent carrier tilt and consequent gouging of the buffer tube. The direct-impingement AR's carrier was driven straight backward pneumatically and carrier tilt was not a problem. All of the gas-piston ARs can suffer from carrier tilt to one degree or another because the carrier is driven rearward from above the centerline axis. The off-axis push causes the tail end of the carrier to want to tilt downward as it enters the buffer tube. LWRC solved the carrier tilt problem by enlarging the diameter of the tail end of the carrier and tapering the rear edge.

The bottom of the LWRC carrier bottoms on the upper receiver and cannot tilt downward. The rear of the carrier cannot go any lower than it was at battery, and the tapered perimeter of the bolt carrier guides the carrier smoothly into the buffer tube.

The clearance cut for the buffer detent is radiused rather than razor-sharp, which prevents gouging of the interior walls of the buffer tube. Shoot your LWRC many thousands of rounds and you will not see any evidence of carrier tilt. You will see no gouging of the buffer tube or bolt carrier. You will not see these things because the LWRC design does not suffer from carrier tilt.

In addition to being larger in diameter and tapered, the tail end of the LWRC bolt carrier features flutes to facilitate draining of water from the buffer tube. The flutes also reduce the bearing surface of the carrier against the buffer and upper receiver,

and act as sand cuts for the accumulation of debris inside the upper receiver and buffer tube, letting LWRC weapons operate in the dirtiest of conditions that would cause other weapons to bind and fail.

LWRC's designers are not bound by the "mil-spec is the word of God" mentality and LWRC does not use standard AR barrels. Note the snakeskin pattern around the chamber reinforce. LWRC barrels are cold hammer-forged from 41V45 steel. Cold hammer-forging involves taking an oversized barrel blank at room temperature (hence the term "cold") and using high-pressure, rotary hammers to forge the barrel blank into shape over a carbide mandrel. The carbide mandrel has negative rifling on its surface and when the barrel blank is forged over the mandrel the blank is impregnated with rifling. The process sounds crude in description but the forging is extremely precise and produces barrels of the highest quality. The rifling formed is perfect and devoid of tool marks. No lapping, polishing, or other finishing methods are required on hammer-forged bores. Hammer-forging also compacts the molecular structure of the barrel, making it denser and stronger. Hammer-forged barrels can take considerably more use and abuse than a cut-, broach-, or button-rifled barrel before any degradation in accuracy or velocity.

Note the general glossiness and color variations of the steel components on an LWRC weapon. Some pieces look jet black while others appear a bluish black. Still other pieces appear dark gray in color. That is NiCorr. LWRC barrels and other steel components are treated with NiCorr rather than being phosphated on the outside and chromed on the inside. NiCorr is a low-temperature, nitro-carburizing treatment followed by an oxidation/impregnation phase.  NiCorr imparts excellent wear resistance, increased yield and fatigue strength, lubricity, and corrosion resistance, while phosphating gives only corrosion resistance. NiCorr leaves a hard, low microfinish, corrosion-resistant surface capable of resisting 360+ hours of accelerated salt spray as tested per ASTM B117.  NiCorr results in minimal distortion or other changing of the pieces' dimensions. NiCorr is more lubricious, harder wearing, more heat- and corrosion-resistant than the hardchrome normally used in military small arms bores, and LWRC barrels will withstand 20,000 rounds before replacement. (The typical service life of a M4 barrel is 6,000 to 10,000 rounds.)

For many decades, American Military chambers and bores have been chrome-plated for corrosion resistance and barrel life. For the plated chamber and bore dimensions to be correct after plating, the components must be cut slightly undersize because of the additional thickness of the plating. And the plating is inherently uneven. It's never perfectly flat, and there are almost always nodules, flaking, pits, or anode burrs with chrome plating. All of these imperfections affect intrinsic accuracy. That is why match and target weapons have unplated bores.

NiCorr suffers from no such disadvantages. Because the NiCorr process is a surface conversion and does not add material like plating, the bores and chambers can be hammer forged exactly to size. NiCorr results in chemical and structural composition changes that can be described as a case hardening to a depth of 0.005” of the alloy leading to increased surface hardness, lower coefficient of friction, enhanced surface lubricity, improved running wear performance, increased sliding wear resistance, enhanced corrosion resistance, and greater heat resistance than industrial hard chrome. NiCorr also has superior corrosion resistance than traditional phosphating for the exterior of the barrels. The combination of hammer-forging and NiCorr finishing results in extremely tough and accurate barrels.

LWRC does not limit NiCorr only to the barrels. The barrel extensions are treated with NiCorr to maximize longevity and prevent set-back of the bolt head.

LWRC treats the gas block with NiCorr to minimize gas cutting and erosion of the gas block and nozzle.

LWRC also treats all of the piston components with NiCorr to smooth operation and maximize component life. The tip of the operating rod does not peen even after thousands and thousands of hits to the bolt carrier's anvil. The NiCorr on these components is effective enough that LWRC's standard practice is to retire the piston components once every four barrel changes. That is about 80,000 rounds, and LWRC retires the piston components for good measure only. Numerous other steel parts in the LWRC uppers and complete weapons are also treated with NiCorr for maximum smoothness and longevity.

LWRC manufactures several different configurations of M6 battle carbines, but the configuration we sell is the M6A2-S. The M6A2-S is not a standard item in the LWRC catalog. Rather, the M6A2-S is built to our specifications on a custom-order basis by LWRC.

The principle difference between the M6A2-S and the standard M6A2 is the location of the gas block. The standard M6A2 is a carbine-length gas system under a midlength forend. Our M6A2-S features the midlength forend of the M6A2, but the gas block is moved forward to form a true, midlength gas system. The S in M6A2-S designates "Stretch", because the gas system is "stretched" from a carbine-length into a true midlength. The advantages of a midlength gas system are several. The gas port is farther away from the chamber, resulting in less gas port erosion, slightly cleaner operation, and slightly lesser dwell time. With lesser barrel in front of the gas block, pressures within the bore and fired case in the chamber are dissipated faster for a given barrel length, facilitating extraction of the empty case from the chamber. Midlength gas systems also transmit less perceived recoil to the shooter compared to carbine-length gas systems.

We offer the M6A2-S in two different configurations: M6A2-S with black finish and 14.7" barrel with permanently attached M16A2 flash suppressor,

and M6A2-S with black finish and 16.1" barrel.

All of our uppers, regardless of finish or barrel length, are fitted with the standard M16A2 flash suppressor.

The flash suppressors fitted to the 14.7" uppers are permanently attached using the pin-and-weld method to achieve the minimal 16" barrel length to remove these uppers from NFA classification. Accordingly, these particular uppers may be attached to any mil-spec AR lower. The pin and weld are purposely left visible to give patent notice to others that these flash suppressors are permanently attached. Some other makers grind and refinish the pin-and-weld job to hide its existence. We opine that leaving the pin and weld visible is the superior method, as it gives patent notice that the flash suppressor is permanently attached. Trying to unthread this flash suppressor without first removing the pin will result in a ruined barrel, and that is much more likely to happen if the pin-and-weld job is not visible. Furthermore, the visible nature of this pin-and-weld job will be greatly welcomed if any law enforcement officer sees the weapon and thinks the flash suppressor might not be permanently affixed in place. The visible pin and weld will show him that it is.

The 16" minimum barrel length for rifles is why the barrel on our uppers is 14.7" long rather than 14.5" long. The standard M16A2 flash suppressor is just a hair too short to reach 16" with a 14.5" barrel. Lengthening the barrel to 14.7" makes permanent attachment of a standard M16A2 flash suppressor possible, while a 14.5" barrel would require a stretched M16A2 flash suppressor, longer aftermarket muzzle device, or a "double nut" attachment method with the standard M16A2 flash suppressor.

The 14.7" uppers look very short. Above is a black upper with 14.7" barrel.

The upper feels just as short in person. It almost looks and feels like a short-barreled upper because there is so little barrel forward of the midlength gas block. But it's not a short-barreled upper. It's a Title I upper for a Title I firearm.

The small size of the 14.7" upper is such that we like small telescopes like the Leupold Prismatics or red dot sights like the various Aimpoints to maintain a sense of proportion between the sighting instrument and the upper.

The flash suppressors fitted to our 16.1" uppers are secured with a mil-spec crush washer but are not permanently affixed in place. Thus, you can change out the flash suppressor to your favorite muzzle device if you want to. If you are the type who likes to play with different muzzle devices, get the 16.1" version.

The 16.1" upper is only slightly longer than the 14.7" upper and looks more proportioned with larger scopes like this Leupold MR/T.

Here is a size comparison between the 14.7" and 16.1" uppers. The buttstocks on these two weapons are adjusted to different lengths, but the viewer will still be able to see a meaningful difference in size between the two upper sizes because of the different barrel lengths.

We are an authorized dealer for LWRC products and our M6A2-S uppers are not some God-forsaken "builds" done in someone's bedroom or garage. Our M6A2-S are factory-original uppers engineered and built by LWRCI and are so marked.

Our uppers are laser-etched with the M6A2-S model designation, so you know these are factory uppers and not aftermarket conversions.

Our uppers are also marked with the American Flag under the rear sight.

Our M6A2-S uppers feature M4 feed ramps. The M4 feed ramps extend lower into the upper receiver than the traditional "rifle ramps" found on the original AR-15 and M16 weapons. The rifle ramps extend only to the periphery of the barrel extension. During development of the M4 carbine, Colt discovered that the M4's greater bolt velocity caused by the carbine-length gas system caused some bullet points to impact the vertical front wall of the upper receiver and fail to feed. The solution was to deepen the feed ramps past the edge of the barrel extension. The M4 feed ramps go low enough that almost any bullet that leaves the magazine will slide along the deeper M4 feed ramps and feed into the chamber.

The forends on our M6A2-S uppers are the Picatinny type to allow the user to configure his personal weapon to his own preferences. The forends attach to the standard AR barrel nut and the barrels are free-floating.

The cross-section of the forend is shown above. Note how the top is taller than the sides and bottom.

The top of the forend continues the upper receiver's Picatinny rail and the sides accept the rail covers, which are included.

The side rails are interrupted by two integral sling swivel sockets on each side.

The sling swivel sockets are machined so as to limit the swing arc of the sling swivel. Sling swivels that swing freely can cause the sling to twist and bind. Not so on the LWRC. Sling swivels are not included.

The Picatinny forend is skeletonized to reduce weight and maximize cooling.

The bottom of the forend features centering pegs that flank the the upper receiver when the forend is installed onto the standard AR barrel nut.

These centering pegs prevent the forend from being turned by the strongest of users, even if a vertical foregrip is fitted to the forend. Many other Picatinny forends are held by friction only and may be twisted on the weapon by strong users who use vertical foregrips. The LWRC system will not turn.

The mounting clamp features helicoil inserts. This way, one is not threading a steel screw into aluminum threads.

The top cover is shaped to give clearance to the gas block and reciprocating piston components.

The top cover is very light in weight. Because the front sight is mounted to the top cover, the top cover is designed that it may be detached easily yet return to zero after reinstallation. Hooked portions of the top cover engage stainless steel pins in the lower portion of the forend.

There are two centering holes machined into the front of the top cover.

The knurled thumbscrews in the lower portion of the forend engage the centering holes in the top cover.

Removing and installing the top cover is as easy as unthreading and threading the two thumbscrews. Each thumbscrew features an O-ring that compresses when the thumbscrew is tightened and prevents the thumbscrew from loosening during use.

If you want to service the piston components, the top cover comes right off. Contrast that with other gas-piston ARs where the piston must be disassembled through the front of the gas block or the entire forend must be removed to give access. The LWRC design is far superior. The top cover returns to zero and only the top cover need be removed to service the piston components.

Here is the assembled forend from above. The stainless steel pins are visible. The top cover falls into the grooves in the lower portion of the forend and the hooked portions of top cover are pushed rearward against the stainless steel pins by the tightening force of the two thumbscrews. In this manner, the top cover returns to zero every time. The front sight, as well as any other sighting devices mounted to the top cover, will return to zero.

This is what the assembled forend looks like with the rail covers fitted.

The M6A2-S has a very integrated appearance with the gas block protruding from the front of the forend. Rather than an abrupt reduction in size from the forend to the barrel, the M6A2-S has a more gradual reduction in diameter from the front sight to the forend to the gas block to the barrel.

Furthermore, the two knurled thumbscrews flank the gas block rather than merely protruding from the front of the forend.

Front and rear sights are the folding type to optimize use with some kind of optical instrument like a scope or a red dot. The weapon above is fitted with a Leupold MR/T scope and LaRue SPR-E mount.

Both front and rear sights feature the LWRC logo,

but were manufactured for LWRC by Troy Industries.

The front sight features the HK-style protective ears. The rear sight has both large and small apertures. The front sight is adjustable for elevation and the rear sight is adjustable for windage.

Each of our uppers also comes with an H2 buffer and a carbine recoil spring. If you have a select-fire lower, the H2 buffer will probably provide the most reliability with the M6A2-S upper. If you have a semi-automatic lower, then the particular buffer you use probably will not matter.

Is your current AR fine? Probably. Are LWRCs better? Absolutely. So why not treat yourself to the best and most incrementally evolved AR in existence?