LWRC's M6A2 Is A Refined, Short- Stroke Gas-piston AR.

TacticalTechnologyBy David FortierPiston PerformerLWRC’s M6A2 is a refined, shortstrokegas-piston AR.In the last few years, the AR markethas become flooded with offerings.A bewildering array of onemanshops and large companies(including big “traditional” guncompanies such as S&W, Remingtonand Ruger) offer almost everyconceivable manner of AR.Because of the mind-numbingnumber of models now available,I have become somewhat jaded.However, I must say that I waspleasantly surprised when I recentlyopened a box from LWRC International.Inside was a handsomecarbine that actually managed tostand out from the AR crowd.For those of you unfamiliar withLWRC International, the Cambridge,Maryland, company hasgrown to become a firm with threefacilities with a whopping 250,000square feet of space and more than50 CNC machine centers, robotic16 • RifleShooter january/february 2010welding, laser cutting and screwmachines along with mil-specpainting capability.Unlike other companies, its focushas been steadfastly fixed uponthe development of a reliable shortstrokegas piston-operated versionof the AR-15. Over the years, it hascontinually refined and improvedits designs and today has more experiencewith gas-piston ARs thanalmost anyone.The result of this work is a patentedself-regulating short-stroke,gas-piston system utilized in theM6 family of rifles and carbines. Itested the M6A2, which you mayrecall graced the cover of the July/August 2009 Rifle Shooter.I was impressed by the obviousattention to detail in both its manufactureand assembly. The polishingon the upper and lower receiverswas a noticeable step above theLWRC’s M6A2 is a good-looking, reliable and accurate gas-piston AR thathandles well up close yet can reach out for those long shots.norm, and the anodizing was flawless.This gun is a head-turner.The rifle is offered in two calibers—5.56x45NATO or the hardhitting6.8mm SPC—and in fourbarrel lengths: 10.5 and 12.7 (bothrestricted), 14.7 and 16.1 inches.The heart of the M6A2 is an upperreceiver that is fitted with amid-length free-floating rail system.Mated to the upper is a matchgrade,cold rotary hammer-forgedmedium-weight barrel made from41V45 steel.The barrel is finished, internallyand externally, in NiCorr for corrosionresistance and long servicelife. LWRC claims this finish outperformstraditional chrome platingand provides a useful barrel lifeof approximately 20,000 rounds.The barrel sports a target crownand is fitted with an A2 flash suppressorand a low-profile gas block.The receiver is finished in a proprietarynickel coating that the companysays provides a hard, permanentlubrication to moving parts.The lower is fairly standard butfitted with a heavier H2 buffer. Thecarbine is nicely dressed with Troyback-up iron sights, a Vltor E-MODstock and Magpul MIAD grip.And that’s just the beginning.Neatly hidden beneath the removableupper handguard is ashort-stroke gas-piston system thecompany describes as lightweight,self-regulating and self-scraping.While gas-piston systems arehardly new to the AR (Taiwan hasissued gas-piston ARs since the1970s), in recent years they havebecome popular in here. Why? Al-www.rifleshootermag.comRISP-100200-TT.indd 1611/24/09 12:01:39 PM

TacticalTechnologythough the standard Stoner directgassystem is well-proven and reliable,like any other system it is lessthan perfect.A gas-piston system addressessome of the criticisms leveled againstStoner’s design—namely that a greatdeal of heat and fouling are injectedinto the bolt carrier. In addition, carbineswith very short barrels oftenlack the reliability of a full-lengthrifle—especially when a sound suppressoris mountedBut there is no free ride. A pistonsystem not only introduces moreparts into the equation, it also pushesthe bolt carrier to the rear in a mannerdifferent than Stoner intended.This latter issue gives rise to a phenomenonreferred to as carrier tilt.When the piston impacts the carrier,the front of the carrier lifts and rotatesslightly as it moves to the rear.LWRC addresses this problem with aredesigned bolt carrier.If not properly set up, a pistonsystem can also negatively affect thebarrel’s harmonics and accuracy,especially on a light barrel. So thelonger a company has been buildingpiston guns the better.My test rifle was fitted with a 14.7-inch barrel with a permanently attachedflash suppressor to bring itout to the legal length. Chamberedfor 5.56x45 NATO, it was rifled with a1:7 inch RH twist.It weighed in at a handy sevenpounds. Overall length is 35.2 incheswith the stock extended and 32 incheswhen collapsed. During testing Imounted a Burris 3-9x40 TAC-30 forprecision work and an Aimpoint MicroT-1 in a LaRue Tactical mount foreverything else.After zeroing, I checked theM6A2’s accuracy from the bench at100 yards. I utilized three loads forthis portion of testing: Black Hills’ 77-grain Mk262 Mod 1, Federal’s AmericanEagle 62-grain FMJ and WolfPerformance Ammunition’s 75-grainSpecificationsLWRC M6A2Type: short-stroke gas-piston ARCaliber: 5.56 NATO (tested), 6.8 SPCCapacity: 30-round detachable boxBarrel: 14.7 in. (tested), cold hammerforged,polygonal rifling, 1:7 RH twistOverall Length: 35.2 in. with stock fullyextendedWeight: 7 lb. without magFinish: hard anodizing and NiCorrStock: Vltor E-MOD collapsing syntheticwith accessory storageTrigger: 7-lb. pull as measuredSights: Troy Industries folding ironsights and 1913 optics railPrice: $2,216Manufacturer: LWRC International,l w r c i.c o m, 410-901-1348steel-case HPBT.While all three loads shot quitewell, Black Hills’ military match loadturned in the best performance, asyou might expect. It posted a respectable1.2 inches at 2,618 fps. With abetter trigger I’m sure I could haveshaved a bit off this. Before remov-Lbh18 • RifleShooter january/february 2010 www.rifleshootermag.comwRISP-100200-TT.indd 1811/24/09 12:01:45 PM

LWRC’s short-stroke gas piston is neatly hiddenbeneath a removable rail. This operating systemhas been the company’s focus since it began.accuracy resultsLWRC M6A2ing the Burris, I putthe M6A2 to work onsteel from 100 to 600yards. Here it provedcapable of consistentlyhitting a six-inchplate at 300 yardsand an 11.5x20-inchLaRue Sniper targetat 500 yards.Switching to theAimpoint, I ran theM6A2 through a varietyof drills from twoto 100 yards. Here thebullet Muzzle Standard Avg.5.56x45 NATO Weight (gr.) Velocity (fps) Deviation Group (in.)Black Hills HPBT Match 77 2,618 12 1.2Federal American Eagle FMJ 62 2,731 44 2.0Wolf HPBT 75 2,600 15 3.0Notes: Accuracy results are averages of four five-shot groups fired from a rest at 100 yards.Velocity figures are 10-shot averages recorded on an Oehler 35P chronograph placed 12 feetfrom the muzzle at an ambient temperature of 86 degrees at 1,030 feet above sea level. Abbreviations:HPBT, hollowpoint boattail; FMJ, full metal jacketLWRC proved quick handling andeasy to hit with. I did note the recoilimpulse is different than a direct-gasgun. Not bad, just different.Reliability was flawless, despitebeing fed a large quantity of steelcaseWolf. No problems of any kindwere encountered; the LWRC simplychugged away. After numerous 30-round magazine dumps, the fore-endbecame almost too hot to hold, butthe bolt carrier remained cool to thetouch.I checked the action and found itto be almost as clean as when I started,although some fouling ventedfrom the system accumulated on theobjective lens of the optic.All in all, I was impressed byLWRC’s M6A2. It’s a good-lookingpiece that performed well. If a pistongun interests you, this is one to consider.It’s expensive at $2,200, but ifyou have the means, an LWRC wouldbe a nice addition to anyone’s AR collection.www.rifleshootermag.com january/february 2010 RifleShooter • 19RISP-100200-TT.indd 1911/24/09 12:01:48 PM