Cmmg Bbl 20" Mt 416ss 6mm Arc Sbn

The CMMG Barrel 20" MT 416SS 6mm ARC SBN is a rifle-length gas system barrel purpose-built for the AR-15 platform in the emerging 6mm ARC caliber. This 20-inch stainless steel barrel features a 5/8-24 threaded muzzle, salt bath nitride finish, and is optimized for precision rifle applications where intermediate-velocity rifle cartridges deliver superior ballistic performance in mid-range engagements. The 6mm ARC, designed for modern sporting rifles and precision work, bridges the gap between 5.56 NATO and larger magnums.

The 20-inch barrel length paired with rifle-length gas system tuning maximizes velocity extraction from 6mm ARC ammunition while maintaining reliable cycling and manageable recoil impulse. The 5/8-24 threaded muzzle accepts standard suppressors, muzzle devices, and compensators in that pattern. The salt bath nitride finish provides corrosion resistance and durability across field conditions. This barrel delivers the velocity characteristics that make 6mm ARC competitive for precision rifle matches, training, and mid-range tactical applications where shooters demand flatter trajectories and extended effective ranges compared to 5.56 NATO.

Built for operators, competitive shooters, and precision rifle builders who have adopted 6mm ARC as a platform upgrade for AR-15 systems, this barrel is suited for bolt-action conversions, semi-automatic builds, and training scenarios where intermediate rifle calibers offer measurable ballistic advantages. The rifle-length gas system ensures consistent bolt carrier acceleration and reliability across quality ammunition loads, reducing the tuning requirements common in shorter gas systems. This is a purpose-built component for those standardizing on modern intermediate cartridges within the AR ecosystem.