Criterion manufactured ADM AR15 Barrels have the following features:
4150 CMV (chrome moly vanadium) steel, 1-8 twist, 300 Blackout chambered, Nitride Finish. The ADM barrel provides the durability of the best material in the family of “Ordinance Grade Steels”, coupled with a Nitride finish for corrosion resistance, reduced maintenance and enhanced accurate life. The barrel is hand lapped prior to finishing to provide the most consistent bore dimensions possible.
Barrels are dimpled for set screw .750 Micro Gasblocks
Chambers are finished, shed, but barrels should be headspaced and installed by a qualified gunsmith.