Jacob Grey Firearms Complete Upper Assembly 5.56 NATO 13in 1-7 Twist 1/2x28 Thread Black

Jacob Grey Firearms Complete Upper Assembly 5.56 NATO 13in 1-7 Twist 1/2x28 Thread Black. 56 NATO and built around a 1/7 twist barrel. 7-sided M-LOK Handguard and 7075 Aluminum Upper Receiver. These uppers have a pistol-length gas system that is combined with a low-profile gas block which provides reliability under any condition. The handguard provides a tactical picatinny rail along the top which allows room for front and rear sights and reduces weight due to less material than standard full le