The LWRCI M6A2 is one of the best examples of the evolution of the AR15 platform.  With an advanced short-stroke gas piston system, free floated rail, VLTOR E-Mod stock, Troy flip-up sights, and Magpul's MOE grip and P-Mag, this rifle represents the best technology available today.

Caliber: 6.8SPC
Weight Without Mag: 7.3 lb
Overall Length: 34.5 inches
Stock Retracted: 31 inches
Magazine: Barrett 30 rd. (6.8SPC)
Rifling:  1 twist in 10 inches, right hand

Technology

LWRCi engineered a solution that retains 80% parts commonality with the issued legacy carbine. The principal improvement comes with the incorporation of a self regulating short stroke gas piston system. The low mass "cup and nozzle" system uses 100% of tapped gas pressure to overcome the mass and resistance of the carbine's moving parts. Once the mass and resistance is overcome, the system vents all excess gas in a "staged vent and dump" of residual gas.

The system is so efficient; it does this in only 6/10ths of an inch of movement. Extraction is far more positive and consistent shot to shot. Regardless of the loading, the piston only uses as much force as is required to cycle the action. No more, no less. The piston stroke is consistent even with a suppressor in use.

Most importantly, none of the trapped gasses are channeled into the bolt carrier group or the receiver of the weapon. That alone eliminates the intensive cleaning regime of the legacy rifle. It also means the bolt carrier group and associated springs are not subject to the searing heat of the tapped gasses which can lead to parts failure. All carbon is vented harmlessly under the hand guards or rail system. LWRC carbines are far more reliable regardless of user maintenance than the legacy direct impingement carbines.

The weapon chamber temperature is lowered as the upper receiver and rail system are no longer searing hot from tapped gasses and can now effectively operate as a heat sink conducting heat away from the receiver extension and chamber.

The short stroke piston system employing a "cup over nozzle" short stroke arrangement limit the reciprocating weight of the piston system and thus prevents disturbing the barrel harmonics and accuracy. With reciprocation of the piston cup, carbon is scraped away from the internal walls of the cup by the fixed ribbed nozzle and blown harmlessly out of the vent holes with the next cartridge fired. This makes the piston system almost maintenance free.

The differences in handling characteristics of LWRC's weapons over the direct impingement legacy weapons are astounding. Recoil is light, muzzle rise is greatly reduced. It is most amazing that this can be accomplished with an LWRC carbine that is ergonomically identical with almost no weight penalty over the legacy direct impingement carbine.