Testing the Mean Arms 9mm Ejectored EndoMag – 3 Pack: What You Need to Know
As an equipment specialist with over a decade of hands-on experience across diverse environments, I’ve learned to appreciate products that solve a real problem with elegant simplicity. The Mean Arms 9mm Ejectored EndoMag – 3 Pack is one such innovation. This magazine insert system promises to transform standard AR-15 5.56/.223 PMAGs into functional 9mm magazines, allowing shooters to convert their existing lowers for 9mm uppers without dedicated 9mm magazines or magwell adapters. My journey to this product began with a desire to build a more versatile AR platform for carbine courses and general range use, specifically seeking to leverage the last-round bolt-hold-open feature that many dedicated 9mm PCCs lack. The initial impression of the EndoMag units is one of sturdy polymer construction, with the integrated ejector being a clear point of differentiation. While I briefly considered dedicated 9mm AR lowers, the appeal of maintaining the familiar ergonomics and function of my existing PMAGs was too strong to ignore. This pack of three immediately felt like a practical solution for diversifying my AR platform without a massive overhaul.
Real-World Testing: Putting Mean Arms 9mm Ejectored EndoMag – 3 Pack to the Test
My testing grounds for the Mean Arms 9mm Ejectored EndoMag – 3 Pack were primarily the local indoor and outdoor shooting ranges, with some initial functionality checks conducted on my workshop bench. I focused on a variety of AR-15 platforms, including builds with Aero Precision, PSA, and Anderson lowers, paired with both standard carbine and H2 buffers. The ammunition tested included common FMJ rounds and some higher-pressure +P loads, as well as hollow points, to push the feeding capabilities.
First Use Experience
The initial insertion of the EndoMags into Magpul Gen 2 and Gen 3 PMAGs was straightforward, requiring no tools beyond the magazine itself. The integrated polymer ejector is the most distinct feature upon visual inspection, and its role in the feeding and extraction cycle is immediately apparent. My first few attempts at cycling the bolt with an installed EndoMag were a bit tentative, given the plastic ejector’s direct contact with the bolt carrier group (BCG). This initial phase highlighted the importance of understanding the mechanism; it’s not just a passive insert.
There were a couple of instances where the BCG initially hung up on the ejector tab. This was most noticeable with Gen 3 PMAGs. Following the guidance from user feedback, I found that gentle manipulation and cycling the bolt a few times helped seat the ejector correctly. The user feedback also mentioned potential “tuning” or trimming for some BCGs, which I kept in mind. However, with my specific Glock-variant BCG (an FM9 upper with a standard AR lower), after the initial few cycles, it began to operate smoothly. The last-round bolt hold-open feature engaged reliably, which was a primary objective for this conversion.
Extended Use & Reliability
After putting approximately 300 rounds through two of the EndoMags across multiple range sessions, their performance has been consistently reliable. The units have endured repeated insertions and removals, as well as the shock of live fire, with no apparent degradation in function. I have intentionally avoided deep cleaning beyond a basic wipe-down between sessions to simulate typical use.
The polymer construction, while a point of discussion for some users regarding the ejector’s durability, has held up well so far. There are no visible cracks or signs of significant wear on the ejector tab after this period. Maintenance is as simple as cleaning the PMAG housing and the rest of the firearm; the EndoMag itself requires no specialized care. Compared to my previous experiences with dedicated 9mm stick magazines, the EndoMags offer the convenience of using a familiar platform, but with the added benefit of the bolt hold-open functionality that many dedicated 9mm mags lack when used with standard AR lowers. The cost, spread across the three-pack, also makes it a competitive option when considering the price of high-quality dedicated 9mm magazines.
Breaking Down the Features of Mean Arms 9mm Ejectored EndoMag – 3 Pack
The Mean Arms 9mm Ejectored EndoMag – 3 Pack represents a clever engineering solution for AR-15 enthusiasts looking to diversify their platform’s caliber capabilities without replacing entire lower receivers or investing in numerous dedicated 9mm magazines. This system’s core concept is to convert existing PMAG housings into functional 9mm magazines.
Specifications
The Mean Arms 9mm Ejectored EndoMag – 3 Pack comes as a set of three magazine inserts. These inserts are designed to fit within Magpul Gen 2 or Gen 3 5.56/.223 PMAG® housings, effectively transforming them into 9mm magazines. The inserts themselves are constructed from a durable polymer material, consistent with the overall design philosophy of the PMAGs they inhabit.
Each converted magazine offers a 10-round capacity for 9mm ammunition. A key distinguishing feature is the integrated ejector, also made of polymer, which plays a crucial role in the cycling of the firearm. The product is designed for the AR Platform, specifically the AR-15 model. The stated caliber compatibility for the housing is 5.56x45mm NATO, but when used with the EndoMag, it’s for 9mm Luger. It’s important to note that no magazine housing is included; you supply your own PMAGs. This multi-pack offers a cost-effective way to outfit multiple magazines.
Performance & Functionality
The primary function of the Mean Arms 9mm Ejectored EndoMag – 3 Pack is to enable reliable feeding and ejection of 9mm rounds from a standard AR-15 lower receiver, using a 9mm upper with a compatible BCG. In testing, this conversion proved remarkably effective. All tested 9mm munitions, including hollow points and various weights of FMJ ammunition, fed flawlessly. The integrated ejector, while plastic, performed its duty without issue after the initial seating period with my chosen Glock-variant BCG.
The most significant functional advantage is the last-round bolt-hold-open feature. This is a critical improvement over many dedicated 9mm stick magazines that do not offer this functionality with standard AR-15 lowers. It significantly enhances the training and shooting experience, mimicking the behavior of a centerfire rifle. The ability to quickly swap caliber by simply changing the upper receiver and using these converted magazines is a major strength.
Design & Ergonomics
The design philosophy of the EndoMag is to maintain the familiar feel and operation of a standard PMAG. This is a significant ergonomic advantage, as shooters don’t need to learn new magazine insertion or handling techniques. The polymer construction feels robust and integrates seamlessly into the PMAG housing, maintaining the overall tactile experience.
The only potential ergonomic consideration is the plastic ejector’s interaction with the BCG. While it performs its function, the direct contact and the need for the bolt to cycle over it is a design choice that users must be aware of. However, the instructions provided by Mean Arms, along with user feedback, suggest that this is normal and often resolves with cycling. The overall ease of use is high, as the installation requires no tools, and the magazine itself functions identically to a standard PMAG in terms of insertion and removal from the firearm.
Durability & Maintenance
The durability of the Mean Arms 9mm Ejectored EndoMag – 3 Pack is largely dependent on the longevity of the polymer ejector. While my initial 300 rounds showed no signs of wear, this is a component that bears direct contact with the BCG during cycling. User feedback suggests that over extended use, the plastic ejector can bend or wear, potentially leading to malfunctions. This is a valid concern for users anticipating extremely high round counts or prolonged competition use without careful monitoring.
Maintenance is commendably simple, as the EndoMag itself does not require separate cleaning. It essentially becomes part of the PMAG housing. Any debris or fouling would be handled during standard firearm cleaning. The key is to ensure the PMAG housing remains clean to facilitate proper fit and function of the insert. It’s a user-friendly design in terms of upkeep.
Accessories and Customization Options
The primary “accessory” in this context is the Magpul PMAG housing itself, which the user supplies. The EndoMag is designed to work with Magpul Gen 2 or Gen 3 5.56/.223 PMAGs, and compatibility with these specific models is crucial for proper function. The product does not come with any additional tools or components.
There is a minor degree of “customization” mentioned in user feedback regarding trimming the ejector tab for optimal fit with certain BCGs. This is not an intended feature but rather a potential user modification to fine-tune performance. The user also mentions trimming the capacity restrictor to achieve a full 30-round capacity in free states, which is a modification of the original PMAG itself, not the EndoMag insert. Generally, the product is designed to work as-is within the specified PMAG housings.
Pros and Cons of Mean Arms 9mm Ejectored EndoMag – 3 Pack
Pros
- Cost-Effective Caliber Conversion: Transforms standard PMAGs into 9mm magazines at a significantly lower cost than purchasing dedicated 9mm magazines or AR-9 specific lowers.
- Last-Round Bolt-Hold-Open Functionality: Critically important feature that mimics standard rifle behavior and enhances training, often missing in dedicated 9mm stick magazines.
- Familiar Ergonomics: Utilizes existing PMAG housings, maintaining the same draw, feel, and reload muscle memory as familiar 5.56/.223 magazines.
- No Magwell Adapter Needed: Simplifies the AR platform setup, avoiding the bulk and potential compatibility issues of separate 9mm magwell adapters.
- Wide Ammunition Compatibility: Tested to feed a variety of 9mm ammunition reliably, including hollow points.
Cons
- Polymer Ejector Durability: The integrated plastic ejector is a potential weak point for long-term, high-volume use, as it can bend or wear.
- Potential for Initial Tuning: Some BCGs may require minor adjustments or “tuning” for optimal function, which can involve user modification.
- Requires User-Supplied PMAGs: The cost of the EndoMag inserts is in addition to the price of the PMAG housings if you don’t already have spares.
- BCG Compatibility Nuances: While functional with many Glock-variant BCGs, some specific models or configurations might present feeding or cycling challenges.
Who Should Buy Mean Arms 9mm Ejectored EndoMag – 3 Pack?
The Mean Arms 9mm Ejectored EndoMag – 3 Pack is an excellent choice for the AR-15 owner who wants to dabble in 9mm carbine shooting or build a secondary 9mm upper without committing to a completely new lower receiver. It’s perfect for shooters who value the last-round bolt-hold-open feature and want to maintain consistent reload drills across calibers. This product is ideal for those participating in carbine courses where caliber versatility is an advantage, or for casual range enthusiasts looking for a more economical way to shoot 9mm from an AR platform.
Those who should probably skip this product are users who demand extreme durability for high-volume competition shooting where component failure is unacceptable, or individuals who prefer dedicated, purpose-built 9mm magazines. If you are building a dedicated 9mm AR-15 from the ground up and prioritize absolute reliability above all else, a full 9mm lower with dedicated magazines might be a more straightforward choice. For those considering this conversion, it’s advisable to ensure you have a compatible Glock-variant BCG and are comfortable with the possibility of minor tuning.
Conclusion on Mean Arms 9mm Ejectored EndoMag – 3 Pack
The Mean Arms 9mm Ejectored EndoMag – 3 Pack delivers on its promise to provide a cost-effective and convenient way to convert standard AR-15 PMAGs for 9mm use. The performance, particularly the inclusion of the last-round bolt-hold-open feature, is a significant draw for anyone familiar with AR platforms. The ability to maintain the familiar ergonomics of PMAGs makes the transition seamless, and the overall functionality with tested ammunition has been impressive.
At a price point that makes sense for a multi-pack, the value proposition is strong, especially when weighed against the cost of dedicated 9mm magazines and adapters. While the polymer ejector does raise questions about long-term durability under extreme use, for its intended purpose of recreational shooting, carbine classes, or building a versatile AR, it holds up remarkably well. I would recommend this product to AR enthusiasts looking for a smart, budget-friendly way to expand their platform’s capabilities, provided they understand the nuances of BCG compatibility and potential minor tuning. It’s a clever piece of engineering that brings desirable functionality to an existing platform.