CMMG RESOLUTE® Mk4 — 5.56mm NATO, 16.1" Barrel, 30-Round, Midnight Bronze Cerakote® | Model 55A9D0B-MB / 55A9D0BMB | UPC 810144722788
Do-It-All 5.56 Carbine With Premium Fit & Finish
The CMMG RESOLUTE® Mk4 is a modern 5.56 rifle built to run hard and shoot straight. With a 16.1-inch barrel for optimal velocity and reliability, a sleek Midnight Bronze Cerakote® finish for rugged weather resistance, and a 30-round magazine (where legal), this AR-15–pattern carbine punches above its weight as a home-defense, range, training, or patrol-ready platform. CMMG’s attention to gas timing, machining, and component fit gives the RESOLUTE that smooth cycling and repeatable accuracy discerning shooters expect.
Whether you’re mounting a red dot for fast CQB work or an LPVO for practical precision, the Mk4 balances just right—stable on a bipod or bag, quick off-hand, and easy to configure with your favorite accessories.
Key Features at a Glance
Caliber: 5.56×45 NATO (compatible with .223 Rem; follow manufacturer guidance)
Barrel: 16.1" (free-float), threaded for muzzle device/suppressor use*
Capacity: 30-round magazine included (where permitted)
Platform: Mk4 (AR-15 pattern) for broad parts and accessory compatibility
Finish: Midnight Bronze Cerakote® for abrasion and corrosion resistance
Handguard: Free-float design, typically M-LOK® compatible for lights, grips, bipods, and rails
Controls: Familiar AR ergonomics with intuitive safety and bolt catch
Models / UPC: 55A9D0B-MB / 55A9D0BMB • 810144722788
*Always verify thread pitch and local laws before installing muzzle devices or suppressors.
Why Shooters Choose the RESOLUTE Mk4
Reliable, Tuned Operation
CMMG’s proven gas system, quality barrel, and precise machining deliver dependable cycling with common 5.56/.223 loads—ideal for training days and defensive readiness.
Free-Float Accuracy
A free-float handguard keeps sling/barricade pressure off the barrel so your point of impact stays consistent, even when shooting from improvised rests.
Cerakote® Durability
The Midnight Bronze Cerakote finish looks phenomenal and shrugs off moisture, solvents, and rough field use—perfect for rain, dust, and hard classes.
AR-15 Ecosystem
Drop in your favorite trigger, stock, optic, and sling. The Mk4 works seamlessly with the industry’s largest aftermarket.
Ideal Use Cases
Home & Property Defense: Light, fast, optics-ready carbine with reliable controls
Training & Classes: Durable finish and free-float handguard for long-course abuse
General Purpose / Ranch Rifle: Versatile setup for varmints, patrol, and range time
Competition Practice: Smooth handling with room to grow into your preferred match configuration
Setup Tips for a Smart Build
Optics: Pair a micro red dot (absolute or lower-1/3 co-witness) for speed, or a 1–6× / 1–10× LPVO for a do-all optic.
Sling & Light: A 2-point sling and white light are must-haves for practical use.
Magazines: Use quality STANAG mags; mark and rotate for reliability.
Break-In & Lube: Generous lubrication during the first few range sessions helps parts settle in smoothly.
Technical Specifications (55A9D0B-MB / 55A9D0BMB)
Caliber: 5.56×45 NATO
Action: Semi-automatic, direct impingement (AR-15 pattern)
Barrel Length: 16.1 inches (threaded)
Handguard: Free-float, typically M-LOK® compatible
Finish: Midnight Bronze Cerakote®
Magazine: (1) 30-round included (capacity subject to local law)
Stock/Grip: AR-standard furniture (variant dependent)
Models: 55A9D0B-MB / 55A9D0BMB
UPC: 810144722788
Small components—trigger style, muzzle device, handguard length—may vary by production run. Always check the product label on your specific rifle.
Frequently Asked Questions
Q: Can it shoot .223 Remington?
A: Yes. A 5.56 NATO chamber safely fires .223 Rem. Always use reputable ammunition and confirm zero with your chosen load.
Q: What magazine type does it use?
A: Standard AR-15 STANAG magazines. One 30-round mag ships with the rifle (where legal).
Q: What is the muzzle thread pitch?
A: Most 5.56 AR barrels use 1/2×28. Confirm your rifle’s spec card before ordering muzzle devices or suppressor mounts.
Q: Is the handguard M-LOK?
A: RESOLUTE trims typically feature M-LOK® slots. Handguard length and exact features can vary—verify your SKU.
SEO-Rich Highlights & Buyer Keywords
CMMG RESOLUTE Mk4 5.56 rifle
16.1" free-float barrel, Midnight Bronze Cerakote
30-round AR-15 carbine, M-LOK handguard
Model 55A9D0B-MB / 55A9D0BMB, UPC 810144722788
AR-15 pattern reliability, optics-ready, general-purpose carbine
Meta Title (SEO)
CMMG RESOLUTE Mk4 — 5.56 NATO, 16.1" Free-Float, Midnight Bronze, 30-Round | 55A9D0B-MB / 55A9D0BMB
Meta Description (SEO)
Shop the CMMG RESOLUTE Mk4 5.56 with a 16.1" free-float barrel, Midnight Bronze Cerakote, M-LOK handguard, and 30-round magazine. AR-15 pattern reliability for defense, training, and range. Model 55A9D0B-MB / 55A9D0BMB, UPC 810144722788.
Structured Data (Product Schema JSON-LD)
Responsible Use Reminder
Follow all local, state, and federal laws regarding firearm purchase, possession, and magazine capacity. Confirm thread pitch and torque specs when adding muzzle devices or optics. Keep the rifle properly lubricated, function-test with your intended ammunition, and practice safe handling and secure storage.
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