Complete 300 AAC BLACKOUT Upper Receiver Assembly
- 9″ 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.
*With barrels shorter than 16″, all NFA rules apply! Specifications subject to change.
- 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.