AR-15 5.56x45 8.5'' and 11'' L.P.R. CARBINE PISTON UPPERS

The adjustable gas block optimizes gas flow into the host firearms operating system. The adjustable gas block has a spring-loaded adjustment knob that releases when pulled forward allowing it to rotate. By rotating the adjustment knob the gas flow is increased or decreased based on one of four provided gas settings. Setting one is optimal for using a silencer, setting two is optimal for normal operations, setting three is optimal for adverse conditions, and setting four either turns the gas flow off optimizing sound reduction and providing for manual operation or provides an extra high gas setting for the host firearm. The system works by precisely metering gas entering the operating system and not by exhausting excess gas into the atmosphere. The gas block features an anti-fouling cavity and the vent hole allows combustion gases to escape from the gas regulator to minimize carbon deposits within the firearm. In addition, the anti-fouling cavity is easily accessible upon disassembly of the regulator system to facilitate the cleaning of the cavity.