Complete 300 AAC BLACKOUT Upper Receiver Assembly
16" Nitrided 1:7: Twist Barrel, threaded 5⁄8−24 AAC 51T BLACKOUT™ Flash Hider "Full Auto" BCG KAC URX Rail Ready to drop onto your AR15/M16/M4 lower! Works with an AR lower with "Mil-Spec" push pin locations.
The 9" and 12.5" AAC 300BLK Uppers are designed for use with a carbine receiver extension, standard GI Buffer Spring, and an H2 Buffer. The 16" AAC 300BLK Upper is designed for use with a carbine receiver extension, standard GI Buffer Spring, and a CARBINE Buffer.