Cmmg Dissent 33A380C-Ab Mk3 8.6Lk 12.5 Brc Arblk

The CMMG Dissent Mk3 in 8.6 Blackout is a modern AR10-platform rifle built for shooters who want serious power in a compact, suppressor-ready package. This rifle takes everything that made 300 Blackout popular—subsonic performance, short-barrel handling, and suppression-friendly ballistics—and scales it up with .338-caliber projectiles on a larger receiver. The 12.5-inch barrel with a 1:3 twist rate is purpose-built for 8.6 BLK, delivering the kind of velocity and energy you'd expect from a bigger round while staying genuinely portable. Whether you're setting up a short-range hunting rig, a home-defense rifle, or a specialized tactical build, this Dissent delivers the features and ergonomics serious shooters demand.

The Mk3 platform itself is billet aluminum (7075 T6) from upper to lower receiver, which means you're holding precision-machined components that won't flex or bind. CMMG's proprietary 11-inch handguard gives you plenty of rail real estate for optics, lights, and other accessories, and the side-charging handle keeps your sight picture intact when you need to run the bolt. The adjustable gas block lets you dial in reliability with your preferred ammunition and suppressor setup, while the ZEROED linear compensator (5/8×24 thread) manages muzzle signature and recoil without the sharp pop of a traditional brake.

Trigger duty falls to a CMMG ZEROED drop-in single-stage trigger with an integrated trigger guard, and the safety selector offers both 60 and 90-degree engagement for your preference. Two Magpul 20-round PMAGs come in the box, and the whole rifle tips the scales at 7.3 pounds—light enough to shoulder all day, rigid enough to shoot precisely. The Cerakote or hard-coat anodized finish protects against the elements, and the 1913 Picatinny rail end cap on the receiver extension gives you solid mounting flexibility.

Key Features

• 8.6 Blackout chambering with 12.5-inch barrel optimized for short-range and suppressed use
• AR10-sized Mk3 billet aluminum upper and lower receivers for rigidity and precision
• Adjustable 0.750 gas block for tuning with suppressors and different ammunition
• Side-charging handle (reversible) keeps your optic-mounting area clear
• Proprietary 11-inch handguard with full rail coverage for accessories
• ZEROED single-stage drop-in trigger with integrated trigger guard
• CMMG ZEROED linear compensator with 5/8×24 threading
• Picatinny rail system for optics, lights, and tactical gear
• Two Magpul 20-round PMAG magazines included
• Compact, suppression-ready configuration at 23 inches and 7.3 pounds

Specifications

Frequently Asked Questions

What is 8.6 Blackout and why would I choose it over 300 Blackout?

8.6 Blackout is a larger-bore cartridge built on the same case design as 300 Blackout but fires .338-caliber projectiles instead of .308. It delivers more velocity and energy from a short barrel and suppresses exceptionally well—performing on par with 300 BLK in terms of subsonic capability while offering the ballistic advantage of a bigger bullet. The Dissent Mk3 platform is purpose-built for this round, with a 1:3 barrel twist optimized specifically for 8.6 BLK performance.

Is this rifle suppressor-ready?

Yes. The 12.5-inch barrel, 1:3 twist rate, and adjustable gas block are all configured for suppressed fire. The muzzle is threaded 5/8×24, which is a standard suppressor thread pattern. The adjustable gas block allows you to fine-tune reliability with your suppressor and ammunition combination.

What magazines does this rifle use?

The Dissent Mk3 in 8.6 Blackout ships with two Magpul 20-round PMAGs. Confirm magazine compatibility with your ammunition supplier and retailer, as magazine performance can vary by load.

Can I swap the charging handle to the other side?

Yes. The Dissent side-charging handle is reversible, so you can configure it for either left or right-hand operation depending on your preference and shooting position.