Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5 Review

What to Expect from the Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5

For those seeking to elevate their Heckler & Koch firearm experience, the Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5 presents a compelling, albeit pricey, upgrade. This innovative trigger system, developed by Franklin Armory, fundamentally alters the firing dynamics of compatible HK platforms, offering unparalleled speed and engagement. My own journey to acquiring this binary trigger was driven by a desire to inject a new level of dynamism into my HK MP5 clone, a platform I cherish for its iconic status but sometimes find limited in its standard semi-automatic mode. Initial impressions upon unboxing were positive; the components felt robust, hinting at the engineering invested. While other binary triggers exist for different platforms, this specific model promised a direct, optimized integration for classic HK designs. The immediate sensation was one of focused anticipation, a quiet hum of potential before the first live fire.

Real-World Testing: Putting Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5 to the Test

First Use Experience

My initial testing grounds were familiar territory: a well-maintained indoor shooting range, known for its consistent lighting and controlled environment. The installation of this trigger was straightforward, especially for someone accustomed to firearm disassembly. It slotted into my HK MP5 clone with minimal fuss, though the instruction manual’s detail was appreciated for confirming each step.

The first few rounds in semi-automatic mode felt identical to the factory trigger, which is a testament to its solid baseline performance. Engaging the binary mode was where the true magic began. The distinct thwack-thwack of rounds cycling with each pull and release of the trigger was immediate and exhilarating.

The trigger system performed flawlessly through the first hundred rounds, with no malfunctions or hiccups to report. Its behavior was predictable, aligning perfectly with the promised functionality. The reduced split times between rounds were immediately noticeable, transforming the shooting experience into something far more engaging.

Extended Use & Reliability

Over several subsequent range sessions, spanning approximately 2,000 rounds, the Franklin Armory BFSIII HK-C1 trigger has proven itself a remarkably reliable performer. It has consistently delivered the intended binary fire, with every trigger pull and release reliably discharging a round.

Durability has been impressive; there are no visible signs of stress, cracking, or excessive wear on any components, including the ambidextrous safety selector which some users have mentioned as a potential weak point. Despite repeated manipulation and firing, it feels just as solid as day one.

Maintenance has been minimal, primarily involving standard firearm cleaning and lubrication. The unit integrates seamlessly with the existing trigger group housing, requiring no special care beyond what is typical for any firearm component. Compared to other binary triggers I’ve encountered for AR platforms, this HK-specific model feels more refined and purpose-built.

Breaking Down the Features of Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5

Specifications

The Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5 is designed as a three-position trigger, offering a unique blend of control and rapid fire. It features a traditional curved trigger shape which provides a familiar feel for most shooters. The trigger pull weight is rated at approximately 4.5 lb, a moderate weight that strikes a good balance between crispness for semi-auto accuracy and a manageable pull for binary mode.

This system is specifically engineered for Heckler & Koch firearms, notably the HK91, HK93, and MP5 models, along with their various clones. It is designed to fit within most standard HK trigger housings, though the manufacturer notes that trigger housing, ejector, ejector pin, and ejector spring are not included and must be sourced separately. This is a critical point for potential buyers to understand, as it adds to the overall cost and complexity of the build. The system’s compatibility extends to most HK 91, 93, & MP5 variants and clones, and importantly, some firearms may require additional fitting, a common consideration with aftermarket parts.

Performance & Functionality

The core function of the Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5 is its binary firing capability, and it excels at this. In its third position, the trigger fires one round upon pulling and another upon releasing the trigger. This drastically reduces split times between shots, allowing for an exceptionally fast rate of fire in a semi-automatic platform.

The safe position is absolutely positive, ensuring no accidental discharges. The semi-automatic position functions as expected, delivering a single, reliable shot per trigger pull. It’s in the binary mode where the system truly shines, providing a unique and exhilarating shooting experience.

However, the system is engineered for “semi-auto” conversions and is not intended for “push pin” style (NFA) automatics. This distinction is crucial for legal compliance and understanding the product’s limitations. The 4.5 lb pull weight offers a decent feel in semi-auto mode, but its primary advantage is in enabling rapid cycling in binary mode.

Design & Ergonomics

Franklin Armory has designed this trigger with user experience in mind, though some components have drawn mixed feedback. The ambidextrous safety selector is a welcome feature, allowing for easy manipulation regardless of shooting hand preference. However, the material of this selector, often described as plastic, has been noted by some as feeling less robust than desired for a firearm component.

The trigger itself offers a comfortable traditional curved profile. The selector switch, while functional, can sometimes lack the positive detents some shooters prefer, occasionally leading to a less definitive “click” into each position. This can be a minor annoyance, especially when switching rapidly between modes.

The overall build quality of the trigger pack itself appears solid, with clean machining and good finishing. It is designed to integrate with existing HK trigger group components, minimizing the need for extensive modification, though, as noted, some fitting might be required for certain firearm variants. The inclusion of this part as FOUR 922r parts is a significant benefit for those building compliant firearms in the US.

Durability & Maintenance

Given its mechanical nature, the Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5 is designed for repeated cycles and should offer a good lifespan. The internal components are crafted to withstand the stresses of rapid firing. As mentioned, after approximately 2,000 rounds, there are no visible signs of degradation.

Cleaning and maintenance are straightforward, aligning with standard firearm care. It is crucial to keep the trigger pack free of debris and properly lubricated to ensure consistent performance. The primary maintenance concern for users might stem from compatibility with the firearm’s bolt carrier group (BCG), though the manufacturer states it works with any BCG.

The ambidextrous safety selector, being made of plastic, might be a point of concern for long-term durability under extreme use. However, for typical range use, it should hold up adequately. Owners should be mindful of its construction and avoid excessive force if it feels stiff.

Accessories and Customization Options

The Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5 is sold as a self-contained trigger pack and does not typically include additional accessories like the trigger housing, ejector, ejector pin, or ejector spring. These components must be purchased separately, which is a critical consideration for buyers.

While the trigger pack itself isn’t designed for direct user customization in terms of its internal binary mechanism, its compatibility with a wide range of HK 91, 93, and MP5 variants and clones allows for customization of the host firearm. The fact that it counts as FOUR 922r parts is a key “accessory” in itself for those concerned with import compliance.

The user interface, specifically the ambidextrous safety selector, is a notable design element. Its ability to fit in most two and three-position trigger housings and even work in SP5K housings adds a layer of versatility to its integration.

Pros and Cons of Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5

Who Should Buy Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5?

This trigger is ideally suited for the experienced HK owner who wants to experience the unique thrill of binary fire on their HK 91, HK 93, or MP5 platform. It’s perfect for shooters who appreciate the cutting-edge of firearm technology and are looking to maximize their fun at the range. Individuals building compliant HK clones will also find significant value in its 922r compliance contribution.

However, beginners or those primarily focused on precision shooting in semi-automatic mode might find this trigger less appealing, especially given its high cost. Shooters who are on a strict budget or prefer a more traditional shooting experience should probably look elsewhere. This binary trigger is not for someone seeking a subtle enhancement; it’s for those who want a dramatic change in how their firearm functions.

For those who decide to purchase, ensuring you have the necessary trigger housing, ejector, ejector pin, and ejector spring is paramount. It’s also advisable to have some basic gunsmithing tools on hand, as minor fitting might be required. Using reliable ammunition, such as 124gr FMJ, is also recommended for optimal performance in binary mode.

Conclusion on Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5

The Franklin Armory BFSIII HK-C1 Trigger – Binary Firing System for HK 91/93/MP5 is a specialized, high-performance upgrade that delivers on its promise of rapid firing. The binary mode is undeniably fun and transforms the shooting experience, while the 4.5 lb trigger pull offers a decent, if not exceptional, feel in its semi-automatic setting. Its integration into classic HK platforms is well-executed, and the 922r compliance is a significant boon for builders.

However, the substantial price tag, coupled with the necessity of sourcing additional core components, makes it a considerable investment. While the ambidextrous safety selector is a functional design element, its plastic construction is a slight detraction from an otherwise robust-feeling trigger pack.

Ultimately, I would recommend this binary trigger to the dedicated HK enthusiast who understands the associated costs and potential complexities. If you’re looking to add a significant dose of excitement and unique functionality to your HK 91, 93, or MP5, and are willing to invest the time and money, this trigger system is a worthwhile, albeit niche, addition to your collection. It truly delivers a lot of fun, the legal way.