CMMG, Inc MK4 Stock Assembly Review

Here’s What I Think of the CMMG, Inc MK4 Stock Assembly

As someone who’s spent over a decade wrestling with gear in environments ranging from dusty workshops to sterile labs and rugged field conditions, I’ve developed a keen eye for what works and what doesn’t. My AR-15 platform is a cornerstone of my equipment, and when it came time to upgrade its ergonomics, I needed a stock that was not only functional but also robust enough for consistent use. The CMMG, Inc MK4 Stock Assembly presented itself as a no-nonsense, reliable option.

My search for a replacement stock began after an older, rather generic adjustable stock started showing its age, with a sticky adjustment lever and a bit too much wobble. I needed something that offered a solid, fixed feel, yet retained the ability to be adjusted if necessary for different shooting positions or gear. The simplicity and solid reputation of CMMG led me to explore their offerings.

Upon receiving the CMMG, Inc MK4 Stock Assembly, my initial impression was one of utilitarian quality. It felt substantial, devoid of unnecessary frills. The polymer felt dense, and the basic design suggested it was built to endure, not just to look good.

I briefly considered a few other premium adjustable stocks, but their complexity and higher price point seemed like overkill for my specific needs. I also looked at some budget options, but their flimsy construction and poor reviews steered me clear. This particular CMMG assembly offered a compelling balance of simplicity and perceived durability for its $59.99 price.

My immediate feeling was one of quiet satisfaction – a sense that this part would simply work without complaint, a welcome sentiment in a world of overly complicated equipment.

Real-World Testing: Putting CMMG, Inc MK4 Stock Assembly to the Test

First Use Experience

My initial testing of the CMMG, Inc MK4 Stock Assembly took place on my home workshop bench, where I performed the installation, followed by range time. The process was straightforward, requiring only basic tools to remove the old buffer tube and install the new one, followed by sliding the stock into place. The CMMG unit slid onto the buffer tube with a satisfyingly snug fit, immediately eliminating the wobble I’d experienced previously.

During my first range session, the stock felt remarkably solid, even during rapid firing drills. Its fixed position, while requiring me to adjust my shooting posture more deliberately, contributed to a consistent cheek weld and a stable platform. I fired approximately 200 rounds, and the stock held its position perfectly, with no slippage or creaking.

The only minor surprise was the simplicity; I’m accustomed to a multitude of adjustment points, and the lack thereof initially made me question if I’d made the right choice. However, the stability it provided quickly alleviated any concerns.

Extended Use & Reliability

After several months of consistent use, involving multiple range trips and even a weekend where the rifle was exposed to light dust and a bit of humidity without issue, the CMMG, Inc MK4 Stock Assembly has proven its mettle. It remains just as rigid and secure as the day I installed it. The polymer shows no signs of stress cracking or deformation, even after being bumped against a workbench a couple of times.

Maintenance has been virtually non-existent. A quick wipe-down with a damp cloth after range sessions is all it requires. Unlike some adjustable stocks that can accumulate debris in their locking mechanisms, this fixed design is incredibly easy to keep clean.

Compared to previous adjustable stocks I’ve used, this fixed CMMG unit offers superior stability and, frankly, a more rugged feel. While budget adjustable stocks often feel flimsy and premium ones can be finicky, this assembly hits a sweet spot of rugged reliability that surpasses many in its price bracket.

Breaking Down the Features of CMMG, Inc MK4 Stock Assembly

Specifications

The CMMG, Inc MK4 Stock Assembly is designed as a direct replacement for standard AR-15 rifle stocks. It includes the stock itself and is built to be compatible with a standard AR-15 buffer tube. The primary material is a durable polymer, which contributes to its lightweight yet sturdy construction.

The Gun Model it’s designed for is the ubiquitous AR-15, and its intended Gun Type is a Rifle. This means it’s engineered to fit the common AR-15 lower receiver extensions, providing a secure and stable connection. The $59.99 price point positions it as an accessible upgrade or replacement.

This simple design means there are fewer points of failure. The polymer construction offers a good balance of impact resistance and weight savings, which is crucial for firearm components. The fact that it’s a complete assembly ready to go out of the box simplifies the upgrade process considerably for the end-user.

Performance & Functionality

In its core function – providing a stable shoulder rest for an AR-15 rifle – the CMMG, Inc MK4 Stock Assembly performs exceptionally well. It offers a consistent cheek weld and a solid anchor point, which is paramount for accurate shooting. The lack of adjustable length-of-pull is, in this case, a strength, as it eliminates wobble and provides a fixed, dependable feel.

The primary strength is its rock-solid stability. I experienced zero wobble or shifting during firing, which directly translates to improved control and accuracy. Its main limitation is the lack of adjustability; while it works perfectly for my stature, individuals needing a specific length of pull for optimal ergonomics might find it restrictive.

For its intended purpose and price point, this stock assembly exceeds expectations in terms of providing a stable and reliable platform. It does its job effectively without unnecessary complexity.

Design & Ergonomics

The design of the CMMG, Inc MK4 Stock Assembly is deliberately minimalist and functional. The durable polymer feels robust to the touch, with a matte finish that offers a decent grip without being abrasive. Its shape is straightforward, featuring a sloped comb that provides a comfortable and consistent cheek weld.

Ergonomically, it’s designed for efficiency. Once mounted, it feels like an integral part of the rifle, not an add-on. The smooth contours prevent snagging on clothing or gear, which is a significant advantage during dynamic movement or when navigating tight spaces.

There’s no real learning curve here; it’s a stock that you mount and use. The simplicity is its greatest ergonomic asset, ensuring it gets out of the way and lets you focus on shooting.

Durability & Maintenance

Based on my experience and the materials used, the CMMG, Inc MK4 Stock Assembly appears to be built for long-term durability under typical shooting conditions. The high-quality polymer is resistant to impacts and environmental exposure. I haven’t encountered any signs of premature wear, cracking, or material degradation.

Maintenance is refreshingly simple; a quick wipe-down is sufficient. Unlike some adjustable stocks that can trap dirt and grit, this fixed design is inherently easy to clean. There are no complex mechanisms that require lubrication or special attention.

The main potential failure point, as with any stock, would be significant external force or impact. However, for its intended use as a rifle stock, its durability is impressive for the price.

Accessories and Customization Options

The CMMG, Inc MK4 Stock Assembly itself is a component of a larger system; it doesn’t typically come with additional accessories beyond what’s needed for installation. However, its design ensures compatibility with a wide range of standard AR-15 buffer tubes.

This assembly is designed to work seamlessly with most aftermarket AR-15 pistol grips, as the stock’s rear interfaces with the lower receiver. There are no direct customization options for the stock itself as it’s a fixed design, but it serves as a stable platform for accessorizing the rest of the rifle. Its strength lies in its plug-and-play compatibility with the AR-15 platform’s standard interface.

Pros and Cons of CMMG, Inc MK4 Stock Assembly

Who Should Buy CMMG, Inc MK4 Stock Assembly?

This CMMG, Inc MK4 Stock Assembly is an excellent choice for AR-15 owners seeking a durable, stable, and no-nonsense stock. It’s ideal for individuals who prioritize reliability over adjustability, such as home defense users, casual range shooters, or those building budget-friendly but robust rifles. Those who appreciate a fixed stock for its consistent feel and lack of moving parts will find this a perfect fit.

However, competitive shooters or those who require precise length-of-pull adjustments for a highly personalized shooting stance might want to look at adjustable stock options. Users who are extremely sensitive to cheek weld height might also consider stocks with adjustable combs.

For a user looking to maximize stability on a budget, I’d recommend ensuring they have a standard AR-15 buffer tube already installed, or budget for one if necessary. A compatible pistol grip would also be a complementary accessory to ensure overall ergonomic harmony.

Conclusion on CMMG, Inc MK4 Stock Assembly

The CMMG, Inc MK4 Stock Assembly delivers precisely what it promises: a sturdy, dependable, and no-nonsense stock for the AR-15 platform. For its $59.99 price, the bulletproof build quality and rock-solid stability it offers are exceptional. It’s a testament to CMMG’s commitment to producing functional, reliable firearm components.

Its value proposition is clear – you get the core benefits of a stable shooting platform without the cost or complexity of adjustable features. While the lack of adjustability might deter some, for many users, especially those prioritizing durability and simplicity, this stock is a fantastic investment. I would wholeheartedly recommend this assembly to anyone looking for a reliable, fixed stock solution that won’t break the bank.