300 AAC Blackout Chambering: The XTS-CUBO10BK upper receiver assembly is specifically chambered for the 300 AAC Blackout cartridge, making it compatible with a wide range of ammunition options and loadings.
Barrel Length: Featuring a 10.5″ barrel length, this upper receiver assembly strikes a balance between compactness and ballistic performance. It is well-suited for pistol and short-barreled rifle configurations.
1:7 Twist Rate: The barrel is equipped with a 1:7 twist rate, which is optimized for stabilizing a variety of bullet weights. This twist rate accommodates both lightweight and heavier projectiles.