LWRC's IC-A5 Upper Receiver is a perfect start to a custom, high-performance AR-build. Originally designed for the U. S. Army's Individual Carbine program the IC-A5 Upper is equipped with a patented short-stroke gas piston system offering the shooter unparalleled reliability and easy maintenance in any conditions. The short-stroke gas piston system is perfectly paired with a nickel-boron coated bolt carrier for unmatched resistance to wear and corrosion while also providing permanent lubricity. Features of the IC-A5 Upper Receiver: LWRCI PROPRIETARY SHORT STROKE GAS PISTON SYSTEM LWRCI ADJUSTABLE 2 POSITION GAS BLOCK LWRCI SKIRMISH BACK UP IRON SIGHTS LWRCI AMBIDEXTROUS CHARGING HANDLE H2 BUFFER CARBINE LENGTH ACTION SPRING LWRC International LWRC IC-A5 .300 Blackout 10.5" 1:7" 1/2x28 Patriot Brown Complete Upper Receiver ICA5U3PBC10