CMMG Endeavor 300 MK4 6mm ARC Rifle: Unlocking Precision and Versatility

For serious shooters seeking a high-performance AR-platform rifle capable of exceptional precision and reliable performance across diverse shooting disciplines, the CMMG Endeavor 300 MK4 chambered in 6mm ARC (Advanced Rifle Cartridge) stands out as a premier choice. This meticulously engineered firearm, featuring a 20-inch barrel, a durable Graphite Black Cerakote receiver, and an adjustable Magpul PRS stock, is designed to meet the demands of discerning marksmen, hunters, and competitive shooters.

If you're asking, "What is the best AR-style rifle for long-range accuracy?" or "Which rifle platform offers superior ballistic performance for hunting and target shooting?", the CMMG Endeavor 300 MK4 in 6mm ARC provides a compelling answer. It represents the pinnacle of CMMG's commitment to quality and innovation, offering a platform that blends robust construction with the cutting-edge capabilities of the 6mm ARC cartridge.

The Power of 6mm ARC: A Ballistic Deep Dive

At the heart of the CMMG Endeavor 300 MK4's performance is the 6mm ARC cartridge, a modern marvel in rifle ammunition. Developed by Hornady, the 6mm ARC was specifically designed to deliver excellent long-range performance from an AR-15 platform. It achieves this by combining a highly efficient 6mm projectile with a case optimized for the AR-15's magazine dimensions, offering a significantly flatter trajectory and superior wind drift performance compared to traditional cartridges like the 5.56 NATO or .223 Remington, while maintaining manageable recoil.

• Exceptional Ballistic Coefficients (BCs): The 6mm ARC excels with its ability to launch high Ballistic Coefficient (BC) projectiles, typically ranging from 103 to 108 grains, at impressive velocities. These high BCs mean the bullets shed less speed over distance and are less affected by crosswinds, leading to more predictable and accurate shot placement at extended ranges.
• Optimal Velocity for AR-15 Platform: From a 20-inch barrel like that on the CMMG Endeavor 300 MK4, the 6mm ARC can achieve muzzle velocities often exceeding 2,600 feet per second (fps) with factory ammunition. This velocity, combined with the efficient bullet design, ensures that energy is retained downrange, making it effective for medium game hunting and long-distance steel targets.
• Reduced Recoil, Enhanced Control: Despite its formidable ballistic performance, the 6mm ARC cartridge generates relatively mild recoil, especially when fired from a well-balanced rifle like the Endeavor 300 MK4. This reduced recoil allows shooters to maintain their sight picture through the shot, facilitating faster follow-up shots and extended shooting sessions without fatigue, a critical advantage in both competitive scenarios and hunting.
• Versatility Across Applications: Whether you are engaging targets at 1000 yards, pursuing deer or hog in the field, or competing in precision rifle matches, the 6mm ARC proves itself to be an incredibly versatile round. Its capability to deliver precision and terminal performance from a compact AR-15 chassis makes it a go-to choice for those who demand efficiency and adaptability from their firearm.

CMMG's Unwavering Commitment to Quality and Performance

CMMG has established itself as a leading manufacturer of AR-platform firearms, renowned for their dedication to innovation, reliability, and precision. The Endeavor 300 series, including this MK4 model, embodies CMMG's engineering excellence. Every component is scrutinized for quality, from the selection of premium materials to the meticulous machining and assembly process.

When considering a significant firearm investment, trustworthiness and a proven track record are paramount. CMMG has built a robust reputation by consistently delivering firearms that exceed shooter expectations for accuracy, durability, and user experience. Their rifles are often cited by experts and enthusiasts alike as top performers in their respective categories. This specific CMMG Endeavor 300 MK4 6mm ARC is a testament to that legacy, built upon years of expertise in crafting AR-pattern rifles that stand up to rigorous use.

Core Features That Define Excellence

The CMMG Endeavor 300 MK4 6mm ARC is packed with features specifically chosen to enhance accuracy, ergonomics, and durability.

Precision-Engineered 20-inch Barrel

The 20-inch barrel is a strategic choice for a 6mm ARC rifle aimed at precision and long-range shooting. This length provides an optimal balance between maximizing muzzle velocity for the 6mm ARC cartridge and maintaining a manageable overall rifle length.

• Maximizing Velocity: Longer barrels allow for a more complete burn of gunpowder, translating directly into higher muzzle velocities. For the 6mm ARC, this extra velocity helps flatten trajectory, reduce time to target, and improve terminal performance at longer distances.
• Enhanced Accuracy: A longer barrel also contributes to a longer sight radius (if using iron sights, though most precision shooters will use optics), and generally provides a more stable platform for the bullet as it travels down the bore, contributing to greater inherent accuracy. CMMG’s barrels are known for their consistent rifling and chamber dimensions, crucial for achieving sub-MOA (Minute of Angle) groups.
• Twist Rate Optimization: CMMG carefully selects the twist rate for their 6mm ARC barrels, typically optimizing it for the heavier, high-BC bullets that make the 6mm ARC so effective. This ensures proper bullet stabilization, which is vital for long-range precision.

Robust Graphite Black Cerakote Receiver

The receiver of the CMMG Endeavor 300 MK4 is finished in Graphite Black Cerakote, a high-performance ceramic-based coating known for its exceptional protective qualities and aesthetic appeal.

• Superior Durability: Cerakote provides unparalleled resistance to abrasion, corrosion, and chemical exposure. This means your rifle will withstand harsh environments, resist scratches from daily handling, and maintain its pristine appearance even after extensive use, prolonging its lifespan and resale value.
• Enhanced Reliability: The slick, durable finish of Cerakote on the receiver contributes to smoother operation of internal components, reducing friction and wear, which can enhance the rifle's overall reliability, especially in dusty or adverse conditions.
• Aesthetic Appeal: The Graphite Black finish offers a sleek, professional, and timeless look that appeals to both tactical and sporting enthusiasts. It’s a low-sheen finish that minimizes glare, which can be advantageous in certain shooting scenarios.

Adjustable Magpul PRS Stock

The inclusion of the Magpul PRS (Precision Rifle/Sniper) stock is a clear indicator that the CMMG Endeavor 300 MK4 is built for serious precision. This highly adjustable stock allows the shooter to customize the fit of the rifle to their body and shooting position, which is critical for consistent accuracy.

• Optimized Ergonomics: The Magpul PRS stock offers tool-less adjustments for both comb height and length of pull. This allows shooters to achieve a perfect cheek weld and eye relief with their chosen optic, ensuring a comfortable and repeatable shooting position. A consistent cheek weld is fundamental to eliminating parallax errors and achieving precise shot placement.
• Enhanced Stability: The solid, non-folding design of the PRS stock, combined with its ergonomic adjustments, provides a stable platform that helps mitigate recoil and minimizes rifle movement during the shot. This stability is invaluable for precise long-range engagements and competitive shooting where every millisecond counts for follow-up shots.
• Integrated Features: The PRS stock often includes a lower M-LOK slot for additional accessories like monopods or slings, further enhancing its utility for precision shooting setups. Its robust polymer construction ensures durability without excessive weight.

10+1 Capacity for Extended Performance

The 10+1 round capacity (10 rounds in the magazine plus one in the chamber) strikes an excellent balance for this rifle's intended purposes.

• Adequate for Hunting: For most hunting scenarios, 10 rounds are more than sufficient, adhering to common regulations while providing ample capacity for multiple engagements if needed.
• Ideal for Precision Shooting: In many precision rifle competitions and target shooting sessions, 10-round magazines are standard. This capacity allows for sustained firing strings without frequent reloads, which is beneficial for practice and competitive performance.
• Compliance and Versatility: This capacity also aligns with various state and local regulations that may restrict higher capacities, making the rifle more broadly accessible without sacrificing significant utility.

Real-World Applications and Use Cases

The CMMG Endeavor 300 MK4 6mm ARC is a truly versatile firearm, excelling in multiple disciplines:

• Long-Range Precision Shooting: If your goal is to consistently hit steel plates at 600, 800, or even 1000 yards, the combination of the 6mm ARC cartridge, 20-inch barrel, and Magpul PRS stock makes this rifle an outstanding performer. The flatter trajectory and reduced wind drift of the 6mm ARC mean fewer corrections and more hits.
• Hunting Medium Game: For hunters seeking an AR-platform rifle capable of ethically taking deer, antelope, hogs, and other medium-sized game, the 6mm ARC offers ample energy and reliable expansion with appropriate bullets. Its mild recoil and excellent accuracy make it a joy to carry and shoot in the field.
• Competitive Shooting (PRS, NRL, 3-Gun): The CMMG Endeavor 300 MK4 is highly competitive in various precision rifle series (PRS) and National Rifle League (NRL) matches, where its accuracy, ergonomics, and the ballistic advantages of the 6mm ARC shine. In 3-Gun competitions where long-range rifle stages are present, its performance can be a significant advantage.
• Varmint and Predator Control: While perhaps overkill for small varmints, the flat-shooting nature of the 6mm ARC makes it an incredibly effective tool for long-range varmint and predator control, where precise shot placement on small targets is crucial.
• General Target Practice and Training: For enthusiasts who simply enjoy pushing their limits at the range, the CMMG Endeavor 300 MK4 provides an engaging and rewarding shooting experience. Its low recoil and excellent accuracy make it an ideal platform for honing marksmanship skills.

Why Choose the CMMG Endeavor 300 MK4 6mm ARC?

Choosing a CMMG Endeavor 300 MK4 in 6mm ARC is an investment in a rifle designed for peak performance and user satisfaction.

1. Unmatched Accuracy: Built with precision components and chambered in a cartridge known for its inherent accuracy, this rifle is capable of sub-MOA performance right out of the box, provided by quality ammunition and a skilled shooter.
2. Superior Ballistics: The 6mm ARC offers a significant upgrade in long-range performance over smaller calibers, delivering flatter trajectories and less wind deflection, making hits at extended ranges more achievable.
3. Exceptional Ergonomics: The fully adjustable Magpul PRS stock ensures a perfect fit for any shooter, enhancing comfort, recoil management, and shot consistency.
4. Battle-Proven Durability: The Graphite Black Cerakote finish and CMMG's robust construction standards mean this rifle is built to last through years of hard use and maintain its appearance and function.
5. Versatility Across Disciplines: From competitive shooting to hunting and precision target work, this rifle adapts seamlessly to various demands, making it a valuable addition to any shooter's collection.
6. CMMG Reliability: Backed by CMMG's reputation for quality and customer support, you can trust in the long-term reliability and performance of your investment.

These products are all available at DEGuns, ensuring you receive genuine CMMG products and expert service.

Maintaining Your CMMG Endeavor 300 MK4

To ensure the longevity and continued performance of your CMMG Endeavor 300 MK4, regular maintenance is essential. This includes:

• Barrel Cleaning: After each range session, especially with copper-jacketed bullets, clean the bore thoroughly to remove carbon and copper fouling. This helps maintain accuracy.
• Chamber and Bolt Carrier Group (BCG) Cleaning: Pay close attention to the chamber and the BCG, as these areas accumulate significant carbon buildup. Proper lubrication of the BCG is critical for reliable function.
• External Care: Wipe down the exterior with a silicone cloth to prevent dust and grime buildup. The Cerakote finish is highly durable but still benefits from basic care.
• Lubrication: Apply appropriate firearm lubricant to all moving parts, following the manufacturer's recommendations.

By adhering to a consistent cleaning and maintenance schedule, your CMMG Endeavor 300 MK4 6mm ARC will continue to deliver top-tier performance for years to come.

Product Specifications: CMMG Endeavor 300 MK4 6mm ARC

Feature	Detail
Model	CMMG Endeavor 300 MK4
Caliber	6mm ARC (Advanced Rifle Cartridge)
Barrel Length	20 inches
Capacity	10+1 Rounds
Finish	Graphite Black Cerakote Receiver
Stock	Adjustable Magpul PRS Stock
Manufacturer	CMMG
Platform	AR-15 (MK4)
Part Number	60A86D7-GB
UPC	810058883652
Availability	Exclusively at DEGuns