The ongoing debate over direct-impingement versus piston-driven ARs is not one that will be decided anytime soon. It is much like hearing a Ford owner and a Chevrolet owner argue over whose truck is best. When it comes to piston-driven guns, LWRC International has been on the leading edge for over 15 years. Located in Cambridge, Maryland, the manufacturing facility includes over 50 state-of-the-art CNC machine centers, laser-cutting machines, screw machines, robotic welders and mil-spec coating booths.


LWRCI’s rifles are approved for use by several federal agencies, including the Drug Enforcement Administration. The company’s short-barrel PSD carbines have become the standard by which other SBRs are measured. In 2013, a Saudi internal security force adopted a specially configured LWRCI PSD chambered in 6.8 SPC. The company is also fielding a new personal defense weapon (PDW) that features a highly refined recoil system, shortened buffer tube and collapsible stock. I recently received an LWRCI M6-IC-SPR for evaluation, and I must admit that it has become one of my favorites. It’s now the rifle I most often have out of the safe.

Gun Details

The foundation of the rifle is the Individual Carbine (IC) configured lower receiver. The IC features a complete set of ambidextrous controls. The safety/selector and bolt release are mirrored on both sides using the same control part. The left-side magazine release is a large paddle that is recessed between two raised ribs. This prevents inadvertent magazine dumps and also provides a tactile guide that assists in locating the paddle. My test rifle was equipped with a Magpul MIAD pistol grip and LWRCI’s adjustable, compact stock, which is similar to a SOPMOD stock. The stock is ergonomically designed with a contoured rubber buttplate that fits well in the shoulder pocket.

RELATED: LWRCI M6 Individual Carbine 5.56mm Rifle Review

The Monoforge upper receiver features a low-profile handguard with threaded positions on its 3, 6 and 9 o’clock axes, allowing the user to mount rail sections where required. LWRCI manufactures its own iron sights from 7075 aluminum. The rear sight consists of a square post that is lifted and then rotated to change aperture settings. The post is also serrated to reduce glare. The front sight consists of a square post that is adjustable for elevation and features a semi-circular guard that is reminiscent of the sights found on an HK MP5. Unlike some designs, the sight base is radiused, eliminating sharp edges that can abrade gear and skin. A low-profile, quick-detach, ambidextrous sling plate is mounted at the rear of the receiver. Finally, the M6-IC-SPR has LWRCI’s large, ambidextrous charging handle.

All LWRCI barrels are made from 41V45 steel alloy and forged from oversized barrel blanks using high-pressure rotary hammers. This process results in near perfect rifling that is molecularly stronger than other forms of rifling. The barrels are also treated with NiCorr, which is “more lubricious, harder wearing [and] more heat and corrosion resistant than normal hard chrome.” The company advertises a barrel life of 20,000 rounds, as compared to 6,000 to 10,000 rounds for standard mil-spec barrels. My test rifle features a 14.7-inch barrel with a permanently pinned AAC Blackout flash suppressor/adaptor. This configuration is the most compact rifle in a non-NFA configuration. The barrel also features LWRCI’s spiral fluting, which reduces weight, improves cooling and looks great!

At the heart of all LWRCI rifles is the company’s patented, self-regulating short-stroke piston system. The design eliminates the gas and carbon buildup in the receiver and bolt carrier group, enhances reliability and reduces felt recoil and muzzle rise. Even with the piston system, the LWRCI rifles retain 80 percent parts commonality with traditional direct impingement rifles. The piston is accessed by loosening two retaining screws and removing the top portion of the rail assembly. The design captures the retaining screws and allows for easy maintenance in the field. As with all LWRCI rifles, the one-piece bolt carrier is coated with a proprietary nickel coating to prevent corrosion and provide increased lubricity. The test rifle came in the new Patriot Brown color with black furniture. The contrast made for a very attractive package.

I set up the M6-IC-SPR for general duty and defensive use. For an optic, I selected Aimpoint’s excellent Patrol Rifle Optic, or PRO, with an integrated mount. Since its introduction in 2011, the PRO has become the most demanded optic in Aimpoint’s product line. It features a 2-MOA dot with four night-vision settings and six daylight settings. Powered by a single 3-volt lithium battery, the PRO’s advanced circuitry provides over 30,000 hours of continuous run time. That is over three years. I also added an Inforce WML weapon light. The WML is a compact, single-battery weapon light with a 200-lumen output and an integral switch. The WML is one of the best weapon lights on the market today.

The final accessory was the addition of a Vickers 2-2-1 sling from Blue Force Gear. Designed in collaboration with Larry Vickers, the sling features a sliding friction buckle that allows the user to easily adjust the length of the sling. The pull-tab on the buckle contrasts visually with the sling, making it easy to locate. I also set up the sling with Blue Force Gear’s Rapid Emergency Detachment (RED) swivel. The RED swivel uses a standard QD locking system with a cable release. The RED will only release when 7 or more pounds of pull is applied in a straight angle. This prevents a release should the cable knob be snagged during normal movement.

Range Time

I installed a Leupold Mark 4 MR/T 2.5-8x36mm M2 tactical scope with a LaRue SPR mount for the 100-yard accuracy testing. Its Tactical Milling Reticle (TMR) and brilliant light-gathering capabilities make the Mark 4 series of scopes ideal for the law enforcement community. I have found this particular scope to be extremely versatile, and it has become my go-to glass for any AR evaluation. The illuminated reticle also provides a low-light capability.

In my opinion, Hornady’s TAP ammunition is the standard by which all duty ammunition should be judged. The 40-grain Urban load is designed to provide instant expansion and complete fragmentation to limit overpenetration. In factory testing, the 40-grain load round expends 100 percent of its energy in 7 inches of bare gelatin, making it ideal for situations where there is a concern with crowds and bystanders. Out of the M6-IC-SPR, the light 40-grain TAP load averaged 3,333 feet per second (fps) and produced a 1.39-inch group. The 55-grain TAP Urban is a favored load for general law enforcement use, as it provides a combination of medium barrier penetration and good terminal ballistics. The 55-grain TAP load averaged 2,826 fps and produced a group that measured 0.74 inches.

ASYM Precision’s 70-grain TSX load consists of a Barnes solid-copper TSX bullet, which offers dramatic expansion, deep penetration and almost 100 percent weight retention. In a tactical application, this translates to effective penetration of common barriers, such as auto glass and sheet metal, with minimal deflection. This load is also designed to work well in short-barrel carbines and, according to the ASYM website, when fired from a 10.5-inch-barreled carbine, retains expansion velocity beyond 200 yards. The ASYM TSX load averaged 2,644 fps and produced a 0.79-inch group.

I also ran some informal drills using the Aimpoint PRO and found that the 14.7-inch barrel improved my ability to acquire targets and transition between them. The little gun tracked true and, thanks in part to the piston operating system, had very little muzzle rise. I also found myself routinely using the ambidextrous magazine and bolt releases.

In the end, the 14.7-inch-barreled M6-IC-SPR proved to be a compact performer that met or exceeded all expectations. It is well suited for general patrol duties, tactical teams and general personal-defense roles. I have evaluated a number of rifles in the past several years, and LWRCI’s M6-IC-SPR is at the top of the list.

For more information, visit or call 410-901-1348.

Up Next

Savage Arms Introduces 64 FV-SR to Suppressor-Ready Rimfire Series

Savage Arms has expanded its line of suppressor-ready rimfire rifles with the introduction of...