Technology

 

 

 

Reports from military organizations who have compiled data, both empirically and through testing, deficits were found related to the issued legacy direct impingement carbine. In response LWRC set out to engineer, develop and produce a line of self regulating short stroke piston operated carbines for military, law enforcement duty and for civilian use. Those deficits of the legacy carbine identified were:

  • Decreased reliability
  • Decreased weapon service life
  • Increase weapon down time due to repairs and maintenance
  • Pronounced muzzle rise and recoil
  • User maintenance intensive
  • Environmentally sensitive
  • Rapid heating in sustained fire leading to small parts and catastrophic failure
  • Bolt lug failure
  • Poor terminal ballistics related to the 5.56 NATO cartridge

LWRC 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.

Terminal Ballistics

While LWRC manufactures weapon in chambered in 5.56mm NATO, LWRC embraced the Rem 6.8mm SPC to address the poor terminal ballistics of the NATO cartridge that are exacerbated by carbine length barrels. 6.8 SPC was developed by military professionals for military professionals. The weapons platform is identical in size and weight yet firing 6.8mm SPC, twice the mass is delivered to the target when compared to 5.56mm NATO. The short pressure curve of 6.8 SPC makes it ideal for use in short barreled carbines and the optimal operating system is a self regulating short stroke piston.

Example:
55 Grain M193 (5.56mm) from a 10.5" barrel = ~2350 Feet per second
110 Grain Rem 6.8mm SPC from a 10.5 barrel = ~2290 Feet per second
Clean, cool, reliable, mission essential.

 

How it Works:

LWRC Legacy Short Stroke Piston

 

Traditional Direct Impingement

Barrel Technology:

LWRCI rifles and carbines utilize cold hammer forged barrels made out of 4150 CMV steel alloy and surface converted with Nitro-Carburizing. Cold hammer forging takes a gun-drilled barrel blank and high pressure rotary hammers compact the barrel blank over a mandrel. This forms perfect rifling devoid of tool marks. It also compacts the molecular structure of the metal making it denser and stronger. These barrels can take a lot more use and abuse than a standard Colt’s barrel before any degradation in accuracy or loss of velocity. Nitro-Carburizing has proved more lubricious, harder wearing, more heat resistant, and corrosion resistant than the hard chrome normally used in the bore. Our barrels can handle 20,000 rounds before needing to be replaced, as compared to 6000-10,000 rounds on a standard M4.