Hands-On with the CMMG, Inc Coll Butt Stock Kit, 6 Position
As an equipment specialist with over a decade of experience across a broad spectrum of demanding environments, I’ve learned to appreciate the subtle nuances that separate functional gear from truly indispensable tools. My work has taken me from the sterile precision of laboratory settings to the gritty realities of workshop repairs and the unforgiving unpredictability of field operations. It was this constant pursuit of reliable, effective equipment that led me to investigate the CMMG, Inc Coll Butt Stock Kit, 6 Position. The specific need arose from a project involving the customization and refurbishment of a well-worn AR-15 platform, where the existing stock was showing significant degradation and a lack of adjustability was hindering ergonomic optimization.
I considered a few other aftermarket options, including some heavier, more tactical-looking stocks, but ultimately sought something that struck a balance between robust construction and practical utility. My initial impression upon unboxing this kit was one of solid, no-nonsense engineering. The materials felt appropriate for their intended use, and the fit and finish suggested a product built for longevity. There’s an immediate sense of “this is going to work” rather than doubt or uncertainty.
Real-World Testing: Putting CMMG, Inc Coll Butt Stock Kit, 6 Position to the Test
My testing environment for this particular kit involved a dedicated workshop setup and several trips to the range for practical firearm handling. The primary focus was on assembly, adjustment, and sustained use during various shooting drills and functional tests. The initial installation was straightforward, fitting securely onto a standard AR-15 receiver extension.
The CMMG, Inc Coll Butt Stock Kit, 6 Position performed admirably under repeated adjustments, moving smoothly between its six distinct positions without any binding or excessive play. I subjected it to moderate recoil impulse and dry-fire exercises, and it maintained its integrity and functionality. Exposure to workshop dust and the occasional light mist of CLP during cleaning did not seem to affect its operation, which speaks well of the chosen materials and sealing.
Over several weeks of regular use, this stock kit has proven itself to be a reliable component. The adjustment mechanism remains positive and secure, holding its set position even under vigorous movement. The Mil-Spec buffer tube and action spring components provided in the kit also performed as expected, contributing to a consistent shooting experience. Maintenance has been minimal, consisting of a simple wipe-down after range sessions and occasional light lubrication of the adjustment points. Compared to some budget stocks I’ve used in the past, which can develop looseness or a gritty feel, this CMMG offering feels substantially more robust and enduring.
Breaking Down the Features of CMMG, Inc Coll Butt Stock Kit, 6 Position
Specifications
This kit is designed to equip a standard AR-15 lower receiver group, providing the essential components for a functional and adjustable stock. The package includes a CMMG 6 Pos Receiver Extension, often referred to as a buffer tube, which is crucial for housing the action spring and buffer. It also contains a Carbine Buffer Assembly, which absorbs recoil energy, and a Carbine Action Spring, providing the necessary tension for the bolt carrier group. The centerpiece is the 6 Position Butt stock Assembly itself, offering user-adjustable length of pull.
The CMMG manufacturer specification indicates a Mil-Spec buffer tube size, which is the industry standard and ensures compatibility with a vast majority of AR-15 receivers. The materials are listed as Alum/Poly, suggesting an aluminum receiver extension and a polymer buttstock, a common and effective combination for balancing durability with weight. With a listed weight of 2 lb and a length of 15 in, this kit provides a substantial yet manageable addition to the firearm. This 6 Position Butt stock allows for approximately 3.5 inches of adjustment, catering to a wide range of shooter physiques and shooting disciplines.
Performance & Functionality
The core function of the CMMG, Inc Coll Butt Stock Kit, 6 Position is to provide a stable, adjustable platform for the rifle. In this regard, it excels. The six positions offer a broad spectrum of length-of-pull adjustments, allowing for precise customization. This is particularly beneficial for transitioning between different shooting stances, accommodating varying clothing layers, or sharing the firearm between individuals of different sizes.
The performance of the buffer and spring system is directly tied to the overall shooting experience, and the components in this kit are well-matched. They work in concert to manage recoil effectively, contributing to a softer shooting feel and faster follow-up shots. The Carbine Buffer Assembly and spring work as intended without any noticeable malfunctions or inconsistencies.
Design & Ergonomics
The design of this stock kit is functional and straightforward, prioritizing utility over aggressive aesthetics. The receiver extension is smoothly machined, and the indexing notches for the stock are well-defined. The buttstock itself features a comfortable polymer cheek weld surface and a textured buttpad that provides adequate grip against clothing or shoulder.
Ergonomically, the adjustment mechanism is intuitive and easy to operate, even with gloves on. A simple push of the castle nut lever allows the stock to slide freely along the receiver extension. Once the desired position is achieved, the stock locks firmly into place, showing no signs of rattling or shifting. The overall feel in hand and against the shoulder is solid, contributing to a more stable shooting platform.
Durability & Maintenance
Based on its construction and materials, this stock kit is built for durability under typical use. The Mil-Spec receiver extension is robust, and the polymer buttstock is designed to withstand impacts and environmental exposure. I’ve observed no degradation in materials or function after my testing period, which included simulated rough handling.
Maintenance is blessedly simple. The receiver extension can be easily cleaned and lubricated, and the buttstock assembly can be removed for more thorough cleaning if needed. There are no complex mechanisms or hidden parts that are difficult to access. Any potential failure points would likely be related to excessive force applied to the adjustment lever or significant impact damage, but these are not common issues with well-maintained equipment.
Accessories and Customization Options
The CMMG, Inc Coll Butt Stock Kit, 6 Position is designed as a complete replacement or upgrade for a standard AR-15 stock setup. It comes as a self-contained unit, meaning the primary components for functionality are included. The kit itself doesn’t come with additional accessories in the traditional sense, like slings or specialized mounts.
However, the 6 Position Butt stock is designed to be compatible with standard AR-15 sling attachment points, such as QD sockets or traditional sling loops, if the user’s specific buttstock model includes them. The CMMG 6 Pos Receiver Extension also adheres to the Mil-Spec standard, meaning it will accept most commercially available AR-15 stocks and buffer tube accessories that also follow the Mil-Spec diameter. This inherent compatibility offers a degree of future customization beyond the kit’s provided parts.
Pros and Cons of CMMG, Inc Coll Butt Stock Kit, 6 Position
Pros
- Complete and functional kit: Includes all necessary components – receiver extension, buffer, spring, and stock – for immediate installation.
- Mil-Spec compatibility: Ensures broad integration with standard AR-15 platforms and aftermarket accessories.
- 6 Position adjustability: Offers a wide range of length-of-pull settings for personalized ergonomics.
- Durable Alum/Poly construction: Balances robustness with manageable weight for practical use.
- Smooth and positive adjustment: The stock slides easily and locks securely without play.
Cons
- Standard aesthetics: While functional, the design is utilitarian and may not appeal to those seeking highly tactical or visually aggressive furniture.
- No integrated sling mounts on all buttstock variations: Some users might need to add aftermarket sling attachment solutions.
Who Should Buy CMMG, Inc Coll Butt Stock Kit, 6 Position?
This CMMG, Inc Coll Butt Stock Kit, 6 Position is an excellent choice for AR-15 owners looking to replace a worn-out or non-adjustable stock, or for those building a new rifle who want a reliable and functional core stock assembly. It’s particularly well-suited for general-purpose shooting, sport shooting, and any application where ergonomic adjustment is beneficial. The Mil-Spec compatibility makes it a safe bet for most AR-15 builds.
Individuals who require extreme lightweight or ultra-compact configurations might consider specialized stocks, but for a balance of performance and value, this kit is hard to beat. If you’re assembling a rifle for the first time or upgrading a basic setup, this provides a solid foundation. For enhanced ergonomics, consider pairing it with a good quality sling that can attach to standard points.
Conclusion on CMMG, Inc Coll Butt Stock Kit, 6 Position
The CMMG, Inc Coll Butt Stock Kit, 6 Position delivers precisely what it promises: a functional, adjustable, and durable stock system for the AR-15 platform. The inclusion of all essential components in one package simplifies the purchasing and installation process, making it an attractive option for builders and upgraders alike. Its performance is consistent, its adjustability is practical, and its construction inspires confidence for long-term use.
Considering its price point and the quality of components provided, the value proposition is very strong. I would confidently recommend this kit to anyone seeking a reliable, adjustable stock that offers excellent functionality without unnecessary frills. It’s a sensible, well-executed upgrade that enhances the usability and comfort of an AR-15.