The Adams Arms Mid-Length Gas Piston complete upper assembly has everything you need and want in a piston upper assembly. The short stroke gas piston operating system is designed to run cooler and cleaner than a standard direct impingement system. Piston systems increase overall reliability while also decreasing the amount of maintenance required to keep he firearm operational. This upper receiver can be connected to any standard AR-15 lower receiver. This upper receiver's muzzle device is pinned and welded.
