Jacob Grey Firearms Complete Upper Assembly 5.56 NATO 13in 1-7 Twist 1/2x28 Thread Black 556N13CUA. 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...
Jacob Grey Firearms Complete Upper Assembly 5.56 NATO 13in 1-7 Twist 1/2x28 Thread Black 556N13CUA. 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...