CMMG Dissent MK4 5.56x45mm NATO 10.50", Left Side Charging Handle, Armor Black, Zeroed Blast Comp, 9.60" M-LOK Handguard, Picatinny End Plate, Fits AR-Platform *UPPER ONLY 55B8D86AB

CMMG DISSENT Mk4 Upper — 5.56x45mm NATO, 10.5" Barrel — Left-Side Charging — Armor Black — ZEROED™ Blast Comp — 9.60" M-LOK® Handguard — Picatinny End Plate — AR-15 Platform (Upper Only) — Model 55B8D86AB — UPC 810097509276 Build a compact, hard-running AR pistol or SBR with the CMMG DISSENT Mk4 10.5" 5.56x45mm Upper. Purpose-engineered for modern shooters, this upper combines a 10.50" 5.56 NATO barrel, left-side charging handle, and ZEROED™ Blast Comp with a lightweight 9.60" free-float M-LOK® handguard and Picatinny end plate. Finished in a durable Armor Black coating, the DISSENT Mk4 upper delivers premium ergonomics, accessory real estate, and reliable performance—ready for your favorite lower, optic, and BCG/charging handle solution. Note: This listing is for the upper receiver group only. See the Included/Not Included section below. Why Choose the CMMG DISSENT Mk4 10.5" Upper Compact, duty-capable length: The 10.50" 5.56 NATO barrel balances portability with practical ballistics for defense, vehicle carry, and compact range builds. Left-side charging handle: Stay on target and run the gun with your support hand—ideal for low-profile manipulations around barriers, prone, or from confined positions. ZEROED™ Blast Comp: Directs blast forward to improve shooter comfort and reduce perceived concussion in tight spaces and team environments. 9.60" free-float M-LOK® handguard: Rigid, lightweight rail with ample M-LOK slots for white lights, hand stops, bipods, and pressure pads—without adding bulk. Armor Black finish: Low-glare, wear-resistant coating that stands up to training cycles and tough field use. Picatinny end plate: Rear rail section supports sling plates, accessories, and clean transitions between setups. Key Specs (Quick Look) Platform: AR-15 / CMMG DISSENT Mk4 upper Caliber: 5.56x45mm NATO (compatible with .223 Rem) Barrel Length: 10.50 inches Muzzle Device: CMMG ZEROED™ Blast Comp (installed) Handguard: 9.60" free-float M-LOK® aluminum Charging: Left-side charging handle (support-hand friendly) Receiver/Finish: Armor Black Rear Interface: Picatinny end plate Model / SKU: 55B8D86AB UPC: 810097509276 Configuration: Upper receiver only (see Included/Not Included) Designed for Real-World Performance From the barricade to the bench, the DISSENT Mk4 upper emphasizes control, speed, and modularity. The left-side charger keeps your firing hand planted while you clear malfunctions or top off, and the free-float handguard preserves accuracy while giving you generous mounting slots for modern accessories. The ZEROED™ Blast Comp pushes concussion forward, making compact builds far more livable on indoor ranges, in vehicles, or during team drills. Build Notes & Compatibility Lower receivers: Pairs with most mil-spec AR-15 lowers. Confirm your buffer system/brace or stock (where legal) and local compliance. BCG & charging handle: This product is sold as UPPER ONLY. Use a quality 5.56/.223 AR-15 BCG and a compatible charging handle or follow CMMG’s guidance for DISSENT-pattern configurations. Gas system & tuning: For suppressed use, consider an adjustable gas block or tuned BCG to optimize reliability and recoil characteristics. Optics & sights: Top rail accepts red dots, LPVOs, and backup sights; the 9.60" handguard supports offset optics and light placements. Ideal Use Cases Home & personal defense: Compact, maneuverable upper for close-to-mid-range engagements. Vehicle/low-profile roles: Short overall length with a blast-managing comp for confined spaces. Training & classes: Free-float M-LOK® rail supports mission-critical accessories and modern sling techniques. Suppressed setups: Pair with a 5.56-rated suppressor and tuned gas for reduced signature (where legal). What’s Included / Not Included Included: CMMG DISSENT Mk4 Upper, 10.50" 5.56 NATO barrel ZEROED™ Blast Comp (installed) 9.60" Free-float M-LOK® handguard Picatinny end plate Left-side charging handle assembly (as equipped from factory) Not Included: Bolt Carrier Group (BCG) Standard rear charging handle (not required for side-charge operation, depending on configuration) Sights/optics, sling, lower receiver assembly, and magazines Always confirm the exact contents of your package; configurations can vary. Installation & Setup Tips Verify safe/clear on your lower; separate upper and lower per AR procedures. Pin the upper to your compatible AR-15 lower receiver. Install your BCG and any required charging components per the DISSENT system guidance. Torque & threadlocker: Follow manufacturer specs for muzzle devices, rail screws, and mounts. Function check thoroughly, then zero your optic (common zeros: 36/50 yards for general use, 100 yards for precision). Care & Maintenance Keep the chamber, bore, and gas system clean; lube friction points per your BCG’s coating/manufacturer. Re-check handguard and muzzle device torque after the first 100–200 rounds. If running suppressed, adopt a more frequent cleaning cycle to manage carbon buildup. Safety & Compliance Use only quality 5.56 NATO / .223 Rem ammunition from reputable manufacturers. Follow all federal, state, and local laws regarding barrel length, braces/stocks, NFA items, and suppressors. Confirm headspace and component compatibility when installing your BCG. SEO-Friendly Highlights (Popular Search Terms) CMMG DISSENT Mk4 upper, 10.5" 5.56 side-charging upper, Armor Black AR-15 upper, ZEROED Blast Comp, 9.60" M-LOK handguard, Picatinny end plate, left-side charging handle, 55B8D86AB, UPC 810097509276, compact 5.56 AR pistol/SBR upper. Compact. Controllable. Mission-ready. The CMMG DISSENT Mk4 10.5" 5.56 Upper in Armor Black pairs a left-side charger, ZEROED™ Blast Comp, and free-float M-LOK® rail to deliver a modern, maneuverable AR build you’ll trust on the range and beyond. "The End"