This is a Ballistic Advantage Barrel known as the Modern chambered in 556NATO, model BABL556015M.
Ballistic Advantage's 5.56 chambered 16 inch M4 Profile Carbine Length Modern Series Barrel is machined from 4150 Chrome Moly Vanadium steel with a QPQ Corrosion Resistant Finish and QPQ coated M4 feed ramp extension.
Features:
4150 Chrome moly vanadium
M4 profile
QPQ finish
Carbine-length gas system
1:7 twist
