Monstrum Side Mounted 12 Gauge Shell Holder Review

The Monstrum Side Mounted 12 Gauge Shell Holder: First Use to Final Thoughts

As someone who’s spent over a decade integrating gear into everything from dusty workshop benches to the unforgiving backcountry, I’ve learned that the most critical accessories are often the ones that fade into the background, just working. The Monstrum Side Mounted 12 Gauge Shell Holder promised to do just that for my Mossberg 590. I was looking for a way to keep spare shells within immediate reach without adding excessive bulk, a common problem with older, heavier side saddle designs. My previous setup, a ten-year-old behemoth, was frankly a nuisance. It was clunky, heavy, and added an unwelcome profile to an already substantial firearm. This Monstrum option, with its sleek, minimalist design and picatinny rail mount, immediately caught my eye as a potential solution. Upon first inspection, the unit felt solid. The polymer appeared robust, and the machining on the picatinny interface looked clean. It wasn’t the heft of a premium aluminum piece, but for its intended function and price point, it offered a promising first impression. I briefly considered a few other basic shell loops, but the integrated rail mount and the promise of an easy, direct installation made this Monstrum offering stand out. My initial thought was one of quiet optimism; this looked like it might finally solve a persistent annoyance.

Real-World Testing: Putting Monstrum Side Mounted 12 Gauge Shell Holder to the Test

First Use Experience

My initial testing was conducted at the local indoor range, a controlled environment where I could precisely measure the impact of the new accessory. I mounted the shell holder onto my Mossberg 590, ensuring the screws were snug but not overtightened. The installation itself was remarkably straightforward, fitting into the existing factory mounting holes without any need for gunsmithing, a significant plus. I tested it with standard 2 ¾-inch 12-gauge shells, specifically focusing on the speed and ease of reloading from the holder during rapid-fire drills. The holder performed admirably under these conditions, allowing for quick access and a smooth transition of shells to the shotgun’s loading gate. There were no hitches or fumbles during the first session, which is always a good sign for any new piece of gear.

Extended Use & Reliability

Over several months, this shell holder has seen consistent use. It’s been on multiple range days, endured the occasional dusty field excursion, and sat patiently in my gun safe. The true test came after cycling through hundreds of shells, including heavier loads like 00 buckshot. Despite the repeated stress of inserting and removing shells, the holder remains as secure as the day it was installed. There are no signs of stress cracks, the shell retention is still firm, and the picatinny mount shows no loosening. I’ve found it remarkably easy to maintain; a quick wipe with a microfiber cloth is usually all it needs. Compared to other shell carriers I’ve used over the years, this Monstrum unit has proven itself to be a durable and reliable performer, especially considering its budget-friendly price point.

Breaking Down the Features of Monstrum Side Mounted 12 Gauge Shell Holder

Specifications

The Monstrum Side Mounted 12 Gauge Shell Holder is designed to accommodate six 12-gauge shotgun shells. Its Picatinny rail mount ensures compatibility with a wide range of shotgun platforms that feature the standard Picatinny interface. The unit is constructed from a durable polymer, which keeps the weight down while providing sufficient resilience for its intended use. It’s engineered with an ambidextrous design, allowing for installation on either the left or right side of the shotgun stock, catering to all shooter preferences. This two-piece unit attaches directly to the factory mounting holes on compatible Mossberg models, including the 500, 590, Shockwave, 535, 835, and 590A1 series shotguns. It’s important to note that older Mossberg shotguns manufactured before 1997 may require different screw sizes (6x48TPI), which are not included with this specific kit.

The capacity of six shells is a practical balance, offering enough spare rounds for quick reloads without significantly increasing the firearm’s overall profile. The polymer construction contributes to a lighter firearm, which is always a benefit during extended handling or tactical movement. Its ambidextrous nature is a thoughtful touch, making it a versatile accessory for any shooter. The Picatinny mount is a standard that offers excellent adaptability, although it’s crucial to confirm compatibility with your specific firearm’s receiver or stock. The direct-mount system, utilizing factory holes, is a major convenience, eliminating the need for specialized tools or modifications.

Performance & Functionality

This shell holder excels at its primary task: keeping spare shells readily accessible. The shell retention is firm enough that shells don’t inadvertently fall out during vigorous movement, yet they are easy enough to draw under pressure. I experienced no issues with shells getting hung up or being difficult to extract, even with gloved hands. The holder performs its function reliably without any moving parts that could fail. It seamlessly integrates into the shooting process, allowing for faster follow-up shots and sustained engagement.

The biggest strength of this accessory is its simplicity and effectiveness. It does exactly what it’s supposed to do, and it does it well, without any unnecessary complications. Its main limitation, if one can call it that, is its fixed capacity; you can’t add more shells to this specific unit. However, for its design and intended purpose, six shells is a well-chosen number. It meets expectations for quick-access reloads perfectly and arguably exceeds them when considering its accessible price point.

Design & Ergonomics

The overall build quality is commendable for the price. The polymer feels robust and durable, with a matte black finish that resists glare and fingerprints. The machining of the Picatinny interface is precise, ensuring a secure lock onto the rail. Ergonomically, the holder is unobtrusive. It sits flush against the side of the receiver or stock, adding minimal bulk.

The design is straightforward, with no complex levers or adjustments. The shell slots are well-defined, guiding the shells into place smoothly. The only minor point of note is the feel of the polymer; it’s not a premium, textured grip, but it’s not slippery either. It’s functional and stays out of the way, which is precisely what you want in this type of accessory.

Durability & Maintenance

From my experience, this shell holder is built for longevity under typical use. The polymer material is resistant to impacts and abrasions. I haven’t noticed any signs of degradation or wear after repeated use and exposure to varying environmental conditions. Maintaining it is as simple as wiping it down with a damp cloth to remove any dust or debris.

There are no complex parts to clean or lubricate, making it virtually maintenance-free. The most likely failure point for any similar accessory would be the mounting screws or the retention mechanism for the shells. So far, both have held up exceptionally well, showing no signs of loosening or fatigue.

Accessories and Customization Options

The Monstrum Side Mounted 12 Gauge Shell Holder comes as a self-contained unit, with no additional accessories included. Its primary “customization” lies in its ambidextrous mounting capability, allowing users to choose which side of their shotgun it attaches to. The unit is also designed to be a two-piece design that mounts together, meaning neither the shell holder nor the rail mount can be used as standalone components.

While there aren’t direct customization options for the holder itself, its Picatinny mount allows for a degree of integration with other Picatinny-compatible accessories if your shotgun platform supports it. However, this holder is specifically designed to work with the shotgun’s receiver or stock, not as a platform for other accessories.

Pros and Cons of Monstrum Side Mounted 12 Gauge Shell Holder

Who Should Buy Monstrum Side Mounted 12 Gauge Shell Holder?

This shell holder is an ideal accessory for any owner of a compatible Mossberg shotgun (500, 590, Shockwave, 535, 835, 590A1) who is looking for an affordable and effective way to increase their immediate firepower. It’s perfect for sport shooters, competition participants, or those who simply want more readily available rounds for home defense or range practice. If you’re looking to upgrade from a heavier, older side saddle or want a minimalist solution, this Monstrum unit is an excellent choice.

Those who require a higher capacity of spare shells (more than six) or who are using shotguns that do not have compatible mounting points might need to look at alternative solutions. For anyone looking to enhance their shotgun’s reload capability without significant investment or modification, this holder is a strong contender. It pairs well with standard 12-gauge shotgun shells and requires no additional accessories to function, though always ensure you have the correct length screws if your shotgun predates 1997.

Conclusion on Monstrum Side Mounted 12 Gauge Shell Holder

The Monstrum Side Mounted 12 Gauge Shell Holder delivers on its promise of providing accessible spare shotgun shells in a practical, no-fuss package. Its value proposition is outstanding; for its modest price of $39.95, you get a durable, well-designed accessory that significantly enhances reload speed and readiness. The ease of installation, ambidextrous functionality, and solid construction make it a standout option in its category.

I would personally recommend this shell holder to any compatible Mossberg shotgun owner looking for an efficient and budget-friendly upgrade. It strikes a perfect balance between form and function, offering just enough capacity without adding unnecessary bulk. If you’re seeking a straightforward solution to keep your spare rounds close at hand, this Monstrum offering is a smart and reliable choice that won’t disappoint.