The Jacob Grey 13″ 5.56 NATO Complete Upper Receiver is built around the JG Billet Aluminum Upper Receiver. The JG Billet Aluminum Upper Receiver does not have a forward assist due to the exacting tolerances and reliability. These uppers have a carbine-length gas system that is combined with a low-profile gas block. The JG 13” handguard features two picatinny rail sections along the top allowing for a front sight. The shortened picatinny sections reduce weight due to less material than standard full-length picatinny rails.
All 5.56 NATO JG Barrels are made from 4150 Chrome Moly Vanadium (CMV) barrel blanks. The increased strength, hardness, and high-temperature stability of CMV barrels are better suited for full-auto and rapid fire. Our complete uppers come with a JG 13” M-LOK handguard giving you plenty of space for all the accessories you could want. The JG 3-Stage Muzzle Brake helps mitigate the recoil impulse and felt recoil.
Complete uppers with barrels under 16″ in length are only for use on AR-15 pistol lowers. Otherwise, the firearm must be registered as a Short-Barreled Rifle (SBR), or have a muzzle device permanently attached to the barrel totaling 16″ barrel length.