Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver Review

First Impressions of Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver

The Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver is not just another AR-15 upper; it’s a long-stroke piston driven system chambered in the hard-hitting 7.62x39mm caliber, a deviation from the standard direct impingement AR-15. This upper receiver promises enhanced reliability and smoother operation, especially appealing for those wanting an AK-47-like round in an AR platform. Primary Weapons Systems is known for its innovative designs and high-quality manufacturing, and this upper receiver seemed like the perfect opportunity to add a unique and dependable option to my collection.

For years, I’ve been chasing the perfect blend of AR ergonomics and AK reliability. The direct impingement system, while effective, can be finicky in harsh conditions. After researching piston-driven AR systems, the Primary Weapons Systems name consistently came up as a leader in the field. I was immediately drawn to the promise of reduced carbon fouling in the bolt carrier group and improved performance with the 7.62×39 round, notorious for its potential feeding issues in standard AR magazines.

The upper receiver arrived well-packaged. Lifting it out of the box, I immediately noticed the robust construction and the quality finish. The anodized aluminum felt smooth and durable, and the overall design gave the impression of a well-engineered piece of equipment. Compared to my standard direct impingement 5.56 upper, the MK116 MOD 1-M felt slightly heavier, but that was expected with the added piston system.

I considered options from other manufacturers, like Adams Arms and Superlative Arms. Ultimately, I chose the Primary Weapons Systems upper because of the company’s reputation for quality and innovation in piston systems, and also for the complete, integrated system approach. The MK116 MOD 1-M offered a complete, ready-to-go solution tailored specifically for the 7.62×39 cartridge, which eliminated the guesswork of mixing and matching parts.

My initial impression was one of excitement mixed with cautious optimism. I was eager to test the claims of enhanced reliability and smoother operation, and hoped that the Primary Weapons Systems MK116 MOD 1-M would live up to the hype. The build quality was impressive, but the real test would be on the range.

Check Best Price HERE

Real-World Testing: Putting Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver to the Test

First Use Experience

My first range trip with the Primary Weapons Systems MK116 MOD 1-M was at an outdoor range in the Nevada desert. I mounted the upper receiver onto a mil-spec lower, paired it with a quality red dot sight, and loaded up several 7.62×39 magazines. The desert environment provided a good initial test, with fine sand and fluctuating temperatures.

The MK116 MOD 1-M performed flawlessly right out of the gate. The long-stroke piston system cycled smoothly, and recoil felt softer compared to some of my DI ARs. I ran several hundred rounds through it that first day, experiencing zero malfunctions, even with a variety of steel-cased and brass-cased ammunition.

The upper required no special adjustments, and the gas system seemed perfectly tuned. After a few magazines, I was hitting targets consistently at 100 yards. I was very impressed by the ease of use; there was no learning curve associated with the piston system. The only “issue” was the need to get used to the different recoil impulse compared to 5.56, but that was a minor adjustment.

Extended Use & Reliability

After several months of use, the Primary Weapons Systems MK116 MOD 1-M continues to impress. I’ve taken it on multiple range trips, exposed it to rain and mud, and even used it during a carbine course. It hasn’t skipped a beat.

Durability has proven to be exceptional. The anodized finish is holding up well, with only minor scratches in high-wear areas. The bolt carrier group remains significantly cleaner than my direct impingement rifles, a clear benefit of the piston system.

Maintenance is straightforward. Cleaning involves wiping down the piston components and lubricating the necessary areas. The reduced carbon buildup means less scrubbing compared to a DI system, saving time and effort. Compared to my previous experiences with direct impingement ARs, the MK116 MOD 1-M offers a noticeable improvement in reliability and ease of maintenance, especially when shooting the notoriously dirty 7.62×39 round.

Breaking Down the Features of Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver

Specifications

The Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver boasts a number of impressive specifications:

• Caliber: 7.62x39mm, offering significant stopping power. This is a key reason many choose this upper, providing an AK-like punch in an AR platform.
• Barrel Length: 16.1 inches, providing a good balance between maneuverability and ballistic performance. This length allows for optimal burn of the 7.62×39 powder, maximizing velocity.
• Gas System Length: Pistol Length, optimized for the 7.62×39 cartridge in a shorter configuration. This contributes to smoother cycling and reduced felt recoil.
• Barrel Twist Rate: 1-10, ideal for stabilizing common 7.62×39 bullet weights. This twist rate ensures accuracy with a variety of ammunition types.
• Muzzle Device: PWS Triad30, effectively mitigates recoil and muzzle flash. This muzzle device enhances control and reduces disturbance to nearby shooters.
• Finish: Anodized, providing a durable and corrosion-resistant coating. This finish protects the upper receiver from the elements and wear.
• Color: Black, a standard and versatile color. This allows for easy matching with various lower receivers and accessories.
• Fabric/Material: T6 7075 Aluminum, ensuring strength and lightweight construction. This material provides a robust yet manageable platform.
• Handguard Length: 15 inches, offering ample space for accessories and a comfortable grip. The longer handguard allows for a wide range of hand positions and accessory mounting options.
• Gun Rail: M-LOK, providing versatile attachment points for accessories. M-LOK is a popular and reliable mounting system.
• Gas System Type: Long-Stroke Piston, known for its reliability and reduced fouling in the action. The long-stroke piston is a signature PWS feature, known for its robust performance.
• Magazine Included: No, allowing the user to choose their preferred 7.62×39 AR magazines.

Performance & Functionality

The Primary Weapons Systems MK116 MOD 1-M excels in its primary function: reliably delivering accurate shots with the 7.62×39 cartridge. The long-stroke piston system ensures smooth and consistent cycling, even with a variety of ammunition types. Accuracy is excellent, easily achieving sub-MOA groups with quality ammunition.

The main strength lies in its reliability and reduced maintenance. The piston system keeps the bolt carrier group cleaner, resulting in fewer malfunctions and easier cleaning. The only area for potential improvement would be the weight, as the piston system adds slightly more weight compared to a direct impingement system. Overall, the MK116 MOD 1-M exceeds expectations, offering a dependable and accurate platform for the 7.62×39 cartridge.

Design & Ergonomics

The build quality is top-notch, with high-quality materials and precise machining. The T6 7075 Aluminum receiver feels solid and durable, and the anodized finish provides excellent protection. The weight, while slightly heavier than a standard AR upper, is manageable and well-balanced.

The ergonomics are excellent, with the 15-inch handguard providing ample space for a comfortable grip. There is a slight learning curve if you’re not familiar with piston systems, but the operation is intuitive and straightforward.

Durability & Maintenance

The Primary Weapons Systems MK116 MOD 1-M is built to last. The robust construction and durable finish ensure long-term reliability, even in harsh conditions. With proper maintenance, this upper receiver should provide years of dependable service.

Maintenance is simple and straightforward, thanks to the piston system. The reduced carbon buildup makes cleaning easier and less frequent. The ability to easily disassemble and clean the piston components is a major advantage.

Accessories and Customization Options

The MK116 MOD 1-M is compatible with a wide range of AR-15 accessories. The M-LOK handguard allows for easy attachment of lights, lasers, and grips. The upper receiver can be easily paired with various lower receivers and trigger systems.

Popular accessories include red dot sights, scopes, and weapon lights. The PWS Triad30 muzzle device can also be swapped out for other muzzle brakes or suppressors compatible with the 7.62×39 caliber.

Pros and Cons of Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver

Check Best Price HERE

Who Should Buy Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver?

The Primary Weapons Systems MK116 MOD 1-M is perfect for shooters who value reliability, durability, and ease of maintenance. It’s an excellent choice for:

• Hunters seeking a hard-hitting and reliable platform for medium-sized game.
• Competitive Shooters who want a consistent and accurate rifle for 3-Gun or similar competitions.
• Tactical Shooters looking for a dependable and low-maintenance rifle for training or duty use.
• Preppers/Survivalists needing a rugged and reliable rifle that can perform in harsh conditions.

This product might not be the best choice for budget-conscious shooters who prioritize affordability above all else. Those extremely sensitive to weight might also find the piston system adds more weight than they prefer.

A must-have accessory is a set of high-quality 7.62×39 AR magazines, such as those from C Products Defense or ASC. A quality optic, such as a red dot or LPVO, is also highly recommended to maximize the platform’s accuracy potential.

Conclusion on Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver

The Primary Weapons Systems MK116 MOD 1-M 16.1in 7.62×39 Upper Receiver is a well-engineered and highly reliable AR-15 upper that delivers on its promises. The long-stroke piston system offers a significant improvement in reliability and ease of maintenance compared to direct impingement systems, especially when shooting the 7.62×39 cartridge. Accuracy is excellent, and the overall build quality is top-notch.

The price is certainly an investment, but the performance and durability justify the cost. For those seeking a dependable and accurate AR-15 chambered in 7.62×39, the Primary Weapons Systems MK116 MOD 1-M is an excellent choice. I wholeheartedly recommend this upper receiver to anyone looking to upgrade their AR platform with a reliable and hard-hitting piston-driven system.