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An Analysis of the Aftermarket Ecosystem and Modernization of the Heckler & Koch MP5

The Heckler & Koch MP5 stands as an undisputed icon in the history of modern small arms. For over half a century, its distinctive silhouette has been synonymous with the world’s most elite counter-terrorism and special operations units.1 Its adoption by over 40 nations and its prominent role in high-stakes operations cemented its reputation as the preeminent submachine gun of the 20th century.2 However, the MP5’s enduring legacy is not solely a product of its revolutionary original design. Its remarkable longevity in the arsenals of these demanding professional users is the direct result of a dynamic and responsive aftermarket ecosystem.

This report will provide a comprehensive technical and tactical analysis of how this ecosystem emerged, not as a matter of simple modernization, but as a critical response to the evolving operational realities that exposed the latent deficiencies of the mid-20th-century platform. The original MP5, a masterpiece of 1960s engineering, was conceived for a world without standardized accessory rails, routine low-light combat, or the widespread use of body armor by operators. As tactical doctrine evolved, these omissions transformed from non-issues into critical capability gaps.

The aftermarket industry did not merely offer cosmetic enhancements; it provided essential engineering solutions that kept the platform viable. This analysis will deconstruct the symbiotic relationship between operator needs and industry innovation, tracing the catalysts for change from the rise of modern counter-terrorism to the paradigm shift in modularity brought about by the USSOCOM SOPMOD program. It will examine the key industry players—SureFire, Knight’s Armament Company, Brügger & Thomet, and others—and their foundational contributions. Ultimately, this report will demonstrate how a dedicated ecosystem of third-party manufacturers transformed the MP5 from a static, albeit brilliant, design into an adaptable and continuously relevant weapons system, ensuring its place in the specialized arsenals of the 21st century.4

Section 1: Foundational Analysis of the Heckler & Koch MP5 Platform

To understand the necessity and nature of the MP5’s aftermarket evolution, one must first conduct a thorough analysis of its foundational design. The platform’s initial success was rooted in a unique combination of advanced mechanical principles that set it apart from all other submachine guns of its era. Yet, within this brilliant design lay inherent limitations that would, decades later, necessitate a comprehensive modernization effort driven by external innovators.

1.1 The Engineering Core: Roller-Delayed Blowback and Closed-Bolt Operation

The heart of the MP5 is its roller-delayed blowback operating system, a direct and scaled-down descendant of the mechanism developed for the Mauser StG 45(M) assault rifle at the end of World War II and later perfected in Heckler & Koch’s own G3 battle rifle.1 This system represents a significant leap in sophistication compared to the simple (or “straight”) blowback mechanisms common to most submachine guns of the period, such as the Uzi or the Ingram MAC-10.1

In a simple blowback system, the breech is held closed only by the mass of the bolt and the pressure of the recoil spring. This requires a very heavy bolt to safely contain the pressures of firing, which in turn leads to a heavy weapon with substantial reciprocating mass, resulting in significant felt recoil and muzzle climb during automatic fire.8 The roller-delayed system circumvents this by using a mechanical disadvantage to slow the bolt’s opening. Upon firing, the cartridge case exerts rearward pressure on the bolt head. However, the bolt head cannot move rearward immediately because two rollers, housed within it, are cammed outwards into recesses in the barrel trunnion. For the bolt head to retract, these rollers must first be pressed inwards. This action is resisted by an angled “locking piece” situated behind the rollers. The rearward force of the cartridge case is thus translated into a much faster rearward movement of the heavier bolt carrier and locking piece assembly, while the bolt head itself is delayed for microseconds.10 This brief delay allows chamber pressures to drop to a safe level before extraction begins, all while using a significantly lighter bolt than a simple blowback design would require.7 The tangible result for the operator is a dramatic reduction in felt recoil and muzzle rise, allowing for exceptionally smooth and controllable automatic fire.7

Complementing this advanced operating system is the MP5’s closed-bolt firing cycle. Most contemporary submachine guns fired from an open bolt, where pulling the trigger releases a heavy bolt that slams forward, strips a round from the magazine, chambers it, and fires it in one continuous motion.14 While mechanically simple and beneficial for cooling during sustained fire, this process introduces significant weapon disturbance just before the shot breaks, making precise single shots difficult. The MP5, by contrast, fires from a closed and locked bolt, much like a rifle.4 The bolt is already forward and the round chambered when the trigger is pulled, meaning the only internal movement is the fall of a small hammer. This minimizes weapon movement and is the primary reason for the MP5’s legendary accuracy, a feature that made it the weapon of choice for surgical applications like hostage rescue, where a precise first shot was paramount.12 This combination of rifle-like accuracy in semi-automatic fire and machine pistol-like controllability in automatic fire made the MP5 a “precision tool” that fundamentally redefined the capabilities of a pistol-caliber firearm.4

1.2 Design Strengths for the Era (1960s-1970s)

When it was introduced in the mid-1960s, the MP5 was a thoroughly modern design that offered significant advantages over its predecessors and many of its contemporaries. Its ergonomics were a marked improvement, with a comfortable pistol grip and intuitive controls that were a scaled version of the G3 rifle, providing a common manual of arms.6 The weapon was relatively lightweight and compact, particularly the MP5A3 variant with its retractable stock, making it highly suitable for use in confined spaces like vehicles and buildings.7

Heckler & Koch engineered the MP5 for uncompromising reliability. The receiver was formed from stamped sheet steel, a robust and efficient manufacturing method, and the barrel was cold hammer-forged for exceptional durability and accuracy.3 To ensure performance in adverse conditions, the metal surfaces were phosphated and then coated with a baked-on lacquer finish, providing high resistance to corrosion and wear.19 The design was validated to function reliably in extreme temperatures, from −40°C to +43°C.7

The sighting system was another area of clear superiority. The MP5 featured a hooded front post and a rotating rear diopter drum, offering four different apertures for varying light conditions and user preference.3 This system was far more precise than the simple open sights found on most submachine guns and contributed greatly to the weapon’s practical accuracy.18 The platform also exhibited a degree of modularity, with interchangeable trigger groups offering different fire control options (e.g., safe/semi/full-auto “SEF” groups or burst-fire variants) and the choice between a fixed polymer stock (A2 models) or a retractable stock (A3 models).1

1.3 Latent Deficiencies: The Seeds of Aftermarket Necessity

Despite its advanced design, the MP5 was a product of its time. The very features that made it successful in the 1960s and 70s contained latent deficiencies that would become significant liabilities as military and law enforcement tactics evolved over the subsequent decades. These were not design flaws in the context of the era, but rather a lack of foresight into the future of tactical operations.

The single greatest deficiency was the complete absence of any native capability for mounting accessories. The MP5’s stamped steel receiver was a smooth, enclosed tube with no integrated rails or standardized attachment points.8 In an era before the proliferation of weapon-mounted optics, lights, and lasers, this was not a consideration. By the 1990s, however, this lack of a universal interface became the platform’s primary handicap, making the addition of mission-essential equipment a complex and non-standardized challenge.22

The weapon’s ergonomics, while excellent for their time, were also a product of a bygone era. The length-of-pull on both the fixed A2 stock and the fully extended A3 retractable stock was designed for an operator wearing little more than a shirt.23 The widespread adoption of ballistic body armor by police SWAT teams and special operations forces in the 1980s and 1990s rendered these stocks too long. Operators wearing bulky vests were forced into an awkward, bladed shooting stance that compromised stability and weapon control, a problem that H&K themselves later acknowledged and addressed in the updated MP5 MLI variant with its multi-position stock.15 Furthermore, early “SEF” trigger groups featured a long, rotating selector lever that was not truly ambidextrous or as ergonomic as later designs.3

Finally, the excellent iron sights, for all their precision, were fundamentally limited. They were optimized for 25-meter engagements and were not designed for field adjustment to other ranges.3 More importantly, their design and the lack of a top rail on the receiver made it impossible to co-witness them with an optic. Adding a red dot sight or other optic required a cumbersome “claw mount” that positioned the optic high above the bore axis, forcing an inconsistent and uncomfortable “chin weld” rather than a solid cheek weld, and offered no backup sighting capability if the optic failed.25 These latent deficiencies, baked into the core design of the MP5, created a clear and compelling need for the aftermarket solutions that would ultimately define its modern identity.

The very engineering brilliance that defined the MP5 also presented its greatest challenge to modernization. The complex, multi-part roller-delayed blowback system, while arguably “overkill” for a pistol-caliber weapon, dictated a receiver design that was fundamentally non-modular.4 Unlike the AR-15 platform, which was conceived with a distinct upper and lower receiver that could be easily separated and modified, the MP5’s receiver is a single, complex, welded and pinned stamped-steel assembly.27 This architectural difference is profound. Upgrading an AR-15’s handguard to a railed version is a simple matter of unscrewing a barrel nut and replacing a component. Modernizing the MP5 required a different philosophy; accessories could not simply replace a part, they had to be added onto the existing structure. This fundamental engineering constraint shaped the entire first generation of MP5 accessories, leading directly to the development of solutions like receiver-gripping claw mounts for optics and full handguard replacements for lights and lasers, a far more complex proposition than the simple bolt-on modularity of its rifle-caliber counterparts.

Section 2: The Catalysts for Change: Evolving Mil/LE Doctrine and Threats

The demand for an MP5 aftermarket ecosystem did not arise in a vacuum. It was driven by a series of seismic shifts in the operational landscape for military special forces and law enforcement tactical units. Three primary catalysts—the rise of modern counter-terrorism, the proliferation of body armor, and a revolutionary new philosophy of weapon modularity—converged in the 1980s and 1990s to create an undeniable imperative for the platform’s evolution.

2.1 The Counter-Terrorism Proving Ground and the Birth of a Need

The 1972 Munich Olympics Massacre was a watershed moment for global security forces. The tragic failure of conventional police to effectively respond to a determined terrorist attack starkly illustrated the need for new, specialized units trained and equipped for high-stakes hostage rescue and counter-terrorism (CT) operations.17 This led to the formation of elite units like Germany’s GSG 9, France’s GIGN, and the proliferation of Special Weapons and Tactics (SWAT) teams in the United States.30 These new organizations required a weapon that was compact, controllable, and precise—a perfect match for the MP5’s capabilities.17

While the MP5 saw quiet adoption by these units throughout the 1970s, it was thrust onto the world stage on May 5, 1980. The live television broadcast of the British Special Air Service (SAS) storming the Iranian Embassy in London during Operation Nimrod had a transformative effect on the weapon’s status.2 Images of the black-clad operators, MP5s at the ready, became iconic overnight.2 This single, highly successful operation created an explosion in global demand. Law enforcement and military units worldwide, seeking to emulate the perceived professionalism and effectiveness of the SAS, made acquiring the MP5 a top priority.5

Crucially, these same iconic images also revealed the platform’s first major deficiency in a modern tactical context. Photographs from Operation Nimrod clearly show SAS operators with large, cylindrical flashlights—likely Maglites or similar models—crudely attached to the top of their MP5s with hose clamps or other improvised mounts.3 This was the first high-profile demonstration of a critical, emerging capability gap: the need for integrated, weapon-mounted illumination for low-light combat. These early, ad-hoc solutions were deeply flawed, often obstructing the weapon’s iron sights and compromising the operator’s ability to aim effectively—a severe tactical trade-off that underscored the urgent need for a professional, purpose-built solution.25

2.2 The Ballistic Imperative and the Rise of Body Armor

While the MP5 was cementing its role in the CT world, a new threat was emerging on the streets and battlefields: the increasing availability of effective body armor. Throughout the 1980s and 1990s, the proliferation of soft body armor capable of defeating standard pistol-caliber rounds began to call into question the terminal effectiveness of the MP5’s 9x19mm Parabellum cartridge.12 For law enforcement, this concern became a brutal reality during the 1997 North Hollywood Shootout. Two heavily armed bank robbers, protected by extensive body armor, engaged Los Angeles police officers in a prolonged firefight, absorbing numerous hits from 9mm pistols and 12-gauge shotguns with little effect.17

The North Hollywood incident was a doctrinal inflection point for American law enforcement. It graphically demonstrated the inadequacy of pistol-caliber weapons against protected threats and triggered a widespread tactical shift within SWAT teams away from submachine guns like the MP5 and towards 5.56x45mm AR-15-based carbines, such as the M4.2 These rifle-caliber weapons could easily defeat soft body armor and offered superior range and barrier penetration capabilities.14

Heckler & Koch was not ignorant of these concerns. In the early 1990s, responding directly to a request from the American FBI, the company developed and released the MP5/10 and MP5/40, chambered in the more powerful 10mm Auto and .40 S&W cartridges, respectively.4 These variants were intended to provide a direct answer to the 9mm’s perceived lack of “stopping power.” However, both were ultimately discontinued by 2000, suggesting that up-calibering the finely tuned roller-delayed blowback system introduced unacceptable trade-offs in reliability, controllability, or parts longevity.16 This failure by the original equipment manufacturer (OEM) to provide a viable ballistic upgrade left the flagship 9mm MP5 increasingly vulnerable to replacement by more powerful platforms.

2.3 The “SOPMOD Effect”: The New Paradigm of Weapon Modularity

The final, and perhaps most significant, catalyst for the MP5’s aftermarket evolution came from the United States Special Operations Command (USSOCOM). In 1989, USSOCOM initiated the Special Operations Peculiar MODification (SOPMOD) program, a project aimed at creating a standardized kit of accessories for the M4A1 carbine.33 This was a revolutionary concept that fundamentally changed how professional end-users viewed their primary weapon. Instead of a fixed tool, the rifle became a modular platform. The SOPMOD kit provided operators with a suite of mission-enhancing accessories—optics, infrared aiming lasers, visible lights, vertical foregrips, and suppressors—that could be easily attached and detached to configure the weapon for any operational requirement.33

The technological heart of the SOPMOD program was the Rail Interface System (RIS), developed by Knight’s Armament Company (KAC).33 The KAC RIS replaced the M4A1’s standard polymer handguard with a quad-rail forearm featuring Mil-Std 1913 Picatinny rails, creating a universal, non-proprietary mounting surface.37 This seemingly simple innovation was transformative. It standardized the interface between the weapon and its accessories, allowing an operator to mount an Aimpoint CompM2 red dot sight, an AN/PEQ-2 infrared laser/illuminator, and a SureFire weaponlight in a secure, repeatable, and ergonomically sound configuration.38

The SOPMOD program created a new professional standard. The immense tactical advantage conferred by a fully accessorized M4A1 became the baseline expectation for any primary weapon system. An operator who had just returned from a mission using a SOPMOD M4 would not accept the limitations of a “slick” MP5 on their next assignment. This created immense institutional pressure from within the world’s most elite units—the MP5’s core user base—to find a way to bring the submachine gun up to the new SOPMOD standard of modularity and capability.

The convergence of these factors created a perfect storm of market demand. The MP5’s very success in the high-profile CT arena, which drove its widespread adoption, also placed it in the hands of the most sophisticated and demanding end-users in the world. These were the same units pioneering new tactics in low-light combat and close-quarters battle, and thus they were the first to experience the platform’s inherent limitations on a large scale. Just as these limitations became undeniable, the SOPMOD program for the M4 provided a clear, tangible template for the solution. The aftermarket industry was not just responding to a vague desire for modernization; it was responding to a specific, well-defined set of capability gaps identified by a highly influential customer base that now knew exactly what it wanted.

Furthermore, the aftermarket thrived precisely where the OEM, Heckler & Koch, appeared to falter. Faced with demands for improved ballistics and enhanced modularity, H&K focused its internal efforts on the former with the short-lived MP5/10 and MP5/40, and ultimately chose platform replacement over adaptation with the introduction of the UMP submachine gun in 1999.3 This strategy left the critical and more immediately solvable problem of accessory integration largely unaddressed by the factory during the crucial decade of the 1990s. This created a market vacuum that innovative third-party companies were perfectly positioned to fill, effectively providing the modernization path that the original manufacturer did not.

Section 3: The Aftermarket Response: Key Players and Foundational Upgrades (The “Classic” Era: ~1985-2005)

The tactical imperatives of the 1980s and 90s created a fertile ground for innovation. A handful of pioneering companies recognized the capability gaps in the factory MP5 and developed foundational products that would define the first generation of its modernization. These were not incremental improvements but transformative solutions that directly addressed the core problems of illumination, modularity, and sighting systems.

3.1 Case Study: SureFire and the Integrated Illumination Solution

The challenge of effectively mounting a light to the MP5 was the first major hurdle to be professionally addressed. The solution came from Laser Products Corporation, founded in 1979 by Dr. John Matthews, a company that would later become synonymous with tactical illumination: SureFire.41 Rather than creating a clamp or mount for an existing handheld flashlight, SureFire developed a truly integrated system: the Dedicated Forend WeaponLight.

The SureFire 628 series (for the full-size MP5) and the more compact 328 series (for the MP5K) were revolutionary products.42 They completely replaced the factory polymer or aluminum handguard with a purpose-built unit that housed a high-intensity incandescent (and later, a far more powerful and durable LED) light source.18 This design was a masterclass in tactical ergonomics. It featured a momentary-on pressure pad switch integrated into the right side of the forend and a constant-on rocker switch on the left.42 This layout allowed the operator to activate the light without altering their normal firing grip, a critical advantage in high-stress situations.48 A patent for this type of integrated forend lighting system was granted in 1989, cementing its innovative status.49 For decades, the SureFire 628 was the gold standard for professional MP5 users, providing the first truly seamless and effective solution for low-light operations.

3.2 Case Study: Knight’s Armament Company and the Rail Adapter System (RAS)

While SureFire solved the illumination problem, the broader issue of modularity remained. The solution to this challenge emerged from the same company that was defining modularity for the US military: Knight’s Armament Company (KAC). Founded by C. Reed Knight Jr., KAC’s work with USSOCOM on the SOPMOD program, born from the observation of troops duct-taping accessories to their rifles, had led to the creation of the M4 Rail Interface System (RIS).50

KAC applied this same philosophy to the MP5, developing the MP5 Rail Adapter System (RAS), part number 97198.52 This product was arguably the single most important development in the history of MP5 modernization. The KAC RAS was a drop-in, two-piece aluminum handguard that provided Mil-Std 1913 Picatinny rails at the 3, 6, 9, and 12 o’clock positions.54 This simple, elegant solution broke the MP5 free from its proprietary, non-modular design. For the first time, an operator could mount the exact same standardized SOPMOD accessories—an AN/PEQ-2 laser, a vertical foregrip, and a separate weaponlight—that they used on their M4A1 carbine.36 This created critical commonality in equipment, training, and logistics for units that employed both weapon systems. The KAC RAS transformed the MP5 from a firearm into a true weapons system, laying the groundwork for all subsequent modular handguards.

3.3 Case Study: Brügger & Thomet, The European Innovator

In Europe, a similar modernization effort was being led by the Swiss firm Brügger & Thomet (B&T). Founded in 1991 by Karl Brügger and Heinrich Thomet, B&T began as a specialized suppressor manufacturer but quickly leveraged its engineering expertise to become a key supplier of tactical accessories for European military and police forces, which were major MP5 users.57

B&T became a one-stop-shop for comprehensive MP5 upgrades. They developed a line of railed handguards, including their well-known Tri-Rail handguard (BT-21174), which served the same function as the KAC RAS and became a direct competitor.59 Recognizing the sighting deficiencies of the platform, B&T also engineered a range of low-profile optic mounts that provided a more stable and lower-height solution for attaching red dot sights than many early claw mounts.58 Their deep familiarity with the platform was so extensive that in 1996, B&T even produced its own semi-automatic variant, the BT96, to navigate restrictive Swiss firearms laws.58 B&T’s extensive catalog of high-quality stocks, mounts, and handguards established them as the premier European source for MP5 modernization, a position they still hold today.

3.4 Enhancing Target Acquisition: The Optics Revolution

The development of reliable, compact, and battery-powered red dot sights, pioneered by the Swedish company Aimpoint in 1975, offered a revolutionary improvement in speed and ease of target acquisition over traditional iron sights.62 For the close-quarters engagements typical of the MP5’s role, the ability to maintain a target-focus with both eyes open and simply place a dot on the threat was a massive tactical advantage.62

US Special Forces began widely adopting red dot sights in the mid-1990s, with early models like the Aimpoint 5000 giving way to the Aimpoint CompM2, which was adopted by the U.S. Army as the M68 Close Combat Optic (CCO) and became a standard issue SOPMOD item by 2000.37 To mount these optics on the MP5, a “claw mount” was required. This type of mount attaches to the small, stamped recesses on the top of the MP5’s receiver. Early designs were often bulky, heavy, and could be knocked out of alignment, failing to hold a consistent zero. This created a demand for more robust solutions, which companies like B&T, and later American firms like Midwest Industries, fulfilled by producing low-profile, lightweight, and rock-solid mounts that clamped securely to the receiver, finally providing a reliable platform for modern optics.26

The following table provides a concise summary of the cause-and-effect relationships that drove the first two decades of MP5 upgrades, linking the evolving tactical problems with the specific engineering solutions and pioneering companies that defined this classic era of modernization.

EraPrimary Tactical DriverIdentified Platform DeficiencyAftermarket Solution CategoryPioneering Products/Manufacturers
1980s–Early 1990sRise of specialized CT/SWAT units; Low-light/night operations become standard doctrine.No native method for mounting illumination tools; ad-hoc solutions obstruct sights.Integrated Weaponlight ForendSureFire 628 Series
Mid-1990s–Early 2000sUSSOCOM SOPMOD program establishes a new standard for modularity; Need for accessory standardization across platforms.No native method for mounting optics; No universal accessory interface.Receiver Claw Mounts for Optics; Railed Handguards (Picatinny)B&T Optic Mounts; Knight’s Armament Company MP5 RAS; B&T Tri-Rail Handguard

Section 4: The Modernized MP5: Maturation and Proliferation of the Ecosystem (c. 2005-Present)

The foundational upgrades of the classic era solved the MP5’s most pressing deficiencies, proving that the half-century-old design could be adapted for modern warfare. The period from the mid-2000s to the present has been characterized by the maturation and proliferation of this aftermarket ecosystem. This new generation of upgrades has focused on refinement, weight reduction, and improved ergonomics, further closing the gap between the MP5 and more contemporary platforms. This phase was also critically enabled by the expansion of the market itself through the availability of high-quality clones.

4.1 Engineering Challenges: Stamped Receivers vs. AR-15 Modularity

Designing accessories for the MP5 presents unique engineering challenges not found in more inherently modular platforms like the AR-15. The MP5’s receiver is its core structural component, manufactured from stamped and welded sheet metal.19 While strong and efficient to produce, this process can result in minor dimensional variations from one firearm to another. Furthermore, the primary mounting surfaces—the claw mount recesses for optics and the handguard attachment points—are less precise and offer less rigidity than the monolithic, machined upper receiver of an AR-15.22 An improperly manufactured or installed AK-style side rail, which shares principles with the MP5 claw mount, can be visibly canted, requiring significant optic adjustment to compensate.68

This stands in stark contrast to the AR-15. The AR platform was designed from the outset for interchangeability. Its architecture, featuring distinct upper and lower receivers joined by two pins, a standardized barrel nut interface for handguards, and a flat-top upper receiver with an integral Picatinny rail, makes it akin to “Legos for adults”.28 This design allows for a vast and competitive market where hundreds of manufacturers can produce components to a common, precise specification, ensuring a high degree of compatibility.27 An AR-15 can be completely reconfigured in minutes with simple tools. The MP5, by contrast, requires more specialized and cleverly designed accessories to work around its fixed, less-precise architecture. This engineering reality means the MP5 aftermarket is, by necessity, smaller and more specialized than the sprawling AR-15 ecosystem.

4.2 Ergonomics for the 21st Century Operator

As the classic era solved the primary mounting problems, the modern era focused on refining the operator’s interface with the weapon. The issue of stock length for users with body armor was a key area of improvement. Companies like B&T and the Swedish firm Spuhr developed multi-position collapsible and folding stocks that offered adjustable length-of-pull, allowing a custom fit for any operator or armor configuration.23 Spuhr’s design also incorporated an adjustable cheek riser, a critical feature for achieving a proper and consistent sight picture when using optics mounted high on claw mounts.23

American manufacturer Magpul Industries, renowned for its ergonomic polymer accessories for the AR-15, eventually turned its attention to the MP5 platform.72 They introduced a comprehensive suite of ergonomic upgrades that brought the weapon’s handling into the 21st century. The Magpul SL Stock provided a modern, adjustable solution, while the SL Grip Module offered a more vertical grip angle, similar to modern carbines, and improved texturing for better control.73 Their Enhanced Selector Kit (ESK) provided an ambidextrous safety selector with improved ergonomics, making manipulation faster and more intuitive.72 These products allowed agencies to significantly upgrade the handling characteristics of their existing MP5 inventories at a relatively low cost.

4.3 Beyond Picatinny: The Advent of M-LOK and Lightweight Systems

By the 2010s, the industry trend in rifle handguards began to shift away from the heavy, cheese-grater-like Picatinny quad-rails of the SOPMOD era. New, lighter, and more user-friendly negative-space attachment systems, primarily Magpul’s M-LOK, became the new standard. These systems provided a smooth, slim handguard surface, with accessories being mounted only where needed via standardized slots.

The MP5 aftermarket quickly adapted to this trend. Companies like Midwest Industries developed lightweight aluminum M-LOK handguards for the MP5.75 These second-generation modular handguards offered significant weight savings and a much more comfortable grip profile compared to the legacy KAC and B&T quad-rails, while still providing ample space for mounting lights, lasers, and grips.65 This evolution mirrored the broader trends in the small arms industry and demonstrated the MP5 aftermarket’s continued ability to keep the platform current.

4.4 Market Expansion and the Role of High-Quality Clones

For much of its history, access to the MP5 platform for smaller law enforcement agencies or civilian purchase was severely restricted by high cost and limited availability from H&K.78 This dynamic began to change dramatically with the emergence of high-quality, reverse-engineered or licensed clones.

Manufacturers such as MKE in Turkey (which produced MP5s under H&K license and whose firearms were imported by companies like Century Arms and, formerly, Zenith), PTR Industries in the United States, and Zenith Firearms’ own US-based production, began offering MP5-pattern firearms at a fraction of the cost of a genuine H&K.2 These clones were not crude copies; many were built on H&K-spec tooling and demonstrated excellent reliability, making the MP5 platform accessible to a vastly larger market.66

This explosion in the number of MP5-pattern firearms in circulation had a profound effect on the aftermarket. It created a larger, more stable, and more diverse customer base. This, in turn, lowered the risk and increased the potential reward for accessory companies to invest in research and development for the platform. The entry of major players like Magpul into the MP5 market was likely enabled by the critical mass of firearms created by the clone manufacturers. This created a powerful, self-reinforcing cycle: the availability of affordable clones created the demand that fueled aftermarket innovation, and the availability of modern, sophisticated accessories made the clones a more viable and attractive purchase for end-users. The clone market and the aftermarket ecosystem thus exist in a symbiotic relationship, with each driving the growth and continued relevance of the other.

Conclusion: A Legacy of Adaptation

The enduring legacy of the Heckler & Koch MP5 is a compelling story of dual excellence. It is, first and foremost, a testament to the initial brilliance of Heckler & Koch’s engineering. The revolutionary roller-delayed blowback mechanism and closed-bolt operation delivered a level of accuracy and controllability that was unmatched in its class for decades, rightfully earning its place as the world’s premier submachine gun.4

However, its continued relevance in the specialized arsenals of the 21st century is a testament to a second, equally important story: the decades-long brilliance of the aftermarket industry’s relentless adaptation. The original MP5 was a product of a tactical environment that no longer exists. Faced with the rise of low-light combat, the proliferation of body armor, and a paradigm shift toward modular weapon systems, the factory-configured MP5 was destined for obsolescence.14

It was the aftermarket ecosystem that saved it. Innovators like SureFire, Knight’s Armament Company, and Brügger & Thomet did not just accessorize the MP5; they re-engineered its capabilities to meet the demands of a new era. They solved the fundamental problems of illumination and modularity. Subsequent generations of manufacturers, from Spuhr to Magpul to Midwest Industries, further refined its ergonomics and brought it in line with contemporary design trends. This constant evolution, driven by direct feedback from the world’s most demanding military and law enforcement users, allowed the platform to remain a viable, specialist tool long after many of its contemporaries were relegated to museums.

While the doctrinal shift towards short-barreled, rifle-caliber carbines for general-purpose tactical use has undoubtedly displaced the MP5 from many frontline roles, its aftermarket-driven evolution has secured its niche. For applications where the unique attributes of a pistol-caliber carbine—namely, exceptionally low recoil, precision, and superior performance with sound suppressors—are paramount, the modernized MP5 remains a premier choice. The MP5 did not simply survive into the 21st century; it was actively and continuously re-imagined by a global ecosystem of innovators who refused to let an iconic design become a historical relic.5 Its story is the ultimate case study in how a symbiotic relationship between a classic platform and a forward-looking industry can create a legacy of enduring adaptation.

Image Source

The main blog image is by MKFI. It was obtained from Wikimedia on 9/21/2025. Description “MP5 submachine gun with both Millog VVLite night vision scope and Aimpoint red dot sight at Millog exhibition stall at Comprehensive security exhibition 2015 in Tampere.”



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Sources Used

  1. [History] Heckler & Koch MP5: A Pop Culture SMG Icon – Pew Pew Tactical, accessed September 2, 2025, https://www.pewpewtactical.com/hk-mp5-history/
  2. History of the H&K MP5 – BYOAR – Build Your Own AR, accessed September 2, 2025, https://www.byoar.com/2021/06/history-mp5/
  3. Heckler & Koch MP5 – Wikipedia, accessed September 2, 2025, https://en.wikipedia.org/wiki/Heckler_%26_Koch_MP5
  4. A Look Back at the Heckler & Koch MP5 | An Official Journal Of The NRA, accessed September 2, 2025, https://www.americanrifleman.org/content/a-look-back-at-the-heckler-koch-mp5/
  5. A Brief History of the MP5 — Zenith Firearms, accessed September 2, 2025, https://zenithfirearms.com/brief-history-mp5/
  6. MP5 : everything you need to know about this machine pistol – Jean Pierre Fusil, accessed September 2, 2025, https://www.fusil-calais.com/en/content/37-heckler-koh-mp5-et-le-cinema
  7. The HK MP5: A Revolutionary Submachine Gun – Luxus Capital, accessed September 2, 2025, https://luxuscap.com/resources-on-guns/heckler-koch/weapon-for-generations-the-mp5/
  8. Inside the MP5, the History and Function of Roller-Delay, accessed September 2, 2025, https://sdi.edu/2021/05/20/inside-the-mp5-the-history-and-function-of-roller-delay/
  9. Delayed Blowback System And PCC Advantages – Show Low MFG, accessed September 2, 2025, https://showlowmfg.com/the-top-4-undeniable-advantages-of-delayed-blowback-systems/
  10. How Does It Work: Roller Delayed Blowback – YouTube, accessed September 2, 2025, https://www.youtube.com/shorts/QN4aR8RufwI
  11. Blowback (firearms) – Wikipedia, accessed September 2, 2025, https://en.wikipedia.org/wiki/Blowback_(firearms)
  12. What makes Hecker & Koch’s MP5 one of the best submachine guns of its time? – Quora, accessed September 2, 2025, https://www.quora.com/What-makes-Hecker-Kochs-MP5-one-of-the-best-submachine-guns-of-its-time
  13. Understanding the Roller-Delayed Blowback Mechanism: Spotlight on HK P9, Korth PRS, HK MP5, and HK G3 – Korriphila, accessed September 2, 2025, https://korriphila.org/understanding-the-roller-delayed-blowback-mechanism-spotlight-on-hk-p9-korth-prs-hk-mp5-and-hk-g3/
  14. Is the HK MP5 now considered an obsolete weapon for hostage rescue? – Reddit, accessed September 2, 2025, https://www.reddit.com/r/WarCollege/comments/13ws8c6/is_the_hk_mp5_now_considered_an_obsolete_weapon/
  15. MP5 – Heckler & Koch, accessed September 2, 2025, https://www.heckler-koch.com/en/Products/Military%20and%20Law%20Enforcement/Submachine%20guns/MP5
  16. Why is the MP5 such an extremely well respected gun? – Quora, accessed September 2, 2025, https://www.quora.com/Why-is-the-MP5-such-an-extremely-well-respected-gun
  17. History of: H&K MP5 | OutdoorHub, accessed September 2, 2025, https://www.outdoorhub.com/stories/2018/08/29/history-of-hk-mp5/
  18. Freedom of Choice: M4 or MP5? – SWAT Survival | Weapons | Tactics, accessed September 2, 2025, https://www.swatmag.com/article/freedom-choice-m4-mp5/
  19. Heckler & Koch MP5 Manual – Indagini Balistiche, accessed September 2, 2025, http://www.indaginibalistiche.it/utlities/manuali/hk_mp5_EN.pdf
  20. Mp5 Features, Specs, and History – The Range 702, accessed September 2, 2025, https://www.therange702.com/blog/mp5-gun-spotlight/
  21. 8 Major HK MP5 Variants — A History – The Mag Life – GunMag Warehouse, accessed September 2, 2025, https://gunmagwarehouse.com/blog/8-hk-mp5-variants-a-history/
  22. Lights, Sights & Silencers: Modernizing The AK | How To Modify | The Primary Source, accessed September 2, 2025, https://blog.primaryarms.com/guide/lights-sights-silencers-modernizing-the-ak-how-to-modify/
  23. MP5 UPGRADES – The Home of Innovation – Spuhr.biz, accessed September 2, 2025, https://www.spuhr.biz/mp5-upgrades
  24. H&K MP5 .22 LR Review: Ultimate Trainer or Range Toy? – Pew Pew Tactical, accessed September 2, 2025, https://www.pewpewtactical.com/hk-mp5-22-lr-review/
  25. The Evolution of the Rifle-Mounted Flashlight – INFORCE light, accessed September 2, 2025, https://inforcelights.com/blogs/inforce-blog/the-evolution-of-the-rifle-mounted-flashlight
  26. Roundup: Accessories For Your MP5-Pattern Firearm | An Official Journal Of The NRA, accessed September 2, 2025, https://www.shootingillustrated.com/content/roundup-accessories-for-your-mp5-pattern-firearm/
  27. How Interchangeable are AR 15 Accessories? – Bootleg Inc, accessed September 2, 2025, https://bootleginc.com/interchangeable-ar-15-accessories/
  28. The AR-15 | The Most Versatile and Modular Firearms Platform Ever Created (BCM 11.5 / BCM Kino 12.5) – YouTube, accessed September 2, 2025, https://www.youtube.com/watch?v=_p9Bu8FuBA8
  29. History of SWAT | Paulding County, GA, accessed September 2, 2025, https://www.paulding.gov/519/History-of-SWAT
  30. A Multi-Method Study Of Special Weapons And Tactics Teams – Office of Justice Programs, accessed September 2, 2025, https://www.ojp.gov/pdffiles1/nij/grants/223855.pdf
  31. SWAT – Wikipedia, accessed September 2, 2025, https://en.wikipedia.org/wiki/SWAT
  32. MP5 – H&K’s Masterpiece of Submachine Gun Design – YouTube, accessed September 2, 2025, https://www.youtube.com/watch?v=ry9LIA5XFlM
  33. SOPMOD – Wikipedia, accessed September 2, 2025, https://en.wikipedia.org/wiki/SOPMOD
  34. SOPMOD Program Overview: Harnessing Technology for the Warfighter PowerPoint Presentation – ID:9301130 – SlideServe, accessed September 2, 2025, https://www.slideserve.com/wehr/nswc-crane-powerpoint-ppt-presentation
  35. Navy SEAL “Coch’s” Career in SOPMOD – YouTube, accessed September 2, 2025, https://www.youtube.com/watch?v=H6nFcledZN0
  36. Knight’s Armament Company – Wikipedia, accessed September 2, 2025, https://en.wikipedia.org/wiki/Knight%27s_Armament_Company
  37. History of SOPMOD, Part I – SWAT Survival | Weapons | Tactics, accessed September 2, 2025, https://www.swatmag.com/article/history-of-sopmod-part-i/
  38. Special Forces gear that regular troops have now, too, accessed September 2, 2025, https://www.wearethemighty.com/mighty-tactical/special-forces-gear-that-regular-troops-have-too/
  39. History of SOPMOD, Part II – SWAT Survival | Weapons | Tactics, accessed September 2, 2025, https://www.swatmag.com/article/history-of-sopmod-part-ii/
  40. SOPMOD history – Punisher Military Store | Tactical equipment in Ukraine, accessed September 2, 2025, https://punisher.com.ua/en/istoriya-sopmod./
  41. SureFire Story, accessed September 2, 2025, https://www.surefire.com/surefire-story/
  42. 628LMF-B Forend WeaponLight – SureFire, accessed September 2, 2025, https://www.surefire.com/628lmf-b-forend-weaponlight/
  43. Surefire Compact Forend Weapon Light HK MP5, HK53, HK94 Black – MidwayUSA, accessed September 2, 2025, https://www.midwayusa.com/product/1026558484
  44. SureFire Dedicated Forend Weaponlights – EuroOptic.com, accessed September 2, 2025, https://www.eurooptic.com/surefire-dedicated-forend-weaponlights
  45. Surefire – 328LMF – Lighted Forearm – HKPARTS, accessed September 2, 2025, https://hkparts.net/handguards-forearms-foregrips/surefire-328lmf-lighted-forearm/
  46. SureFire 628LMF-B Forend LED Weapon Light for H&K MP5, HK53, HK94 – B&H, accessed September 2, 2025, https://www.bhphotovideo.com/c/product/1456469-REG/surefire_628lmf_b_dedicated_submachine_gun.html
  47. SureFire Classic Series Dedicated Forend Weapon Light for H&K MP5 / 94 / 53 628, accessed September 2, 2025, https://www.opticsplanet.com/surefire-weaponlights-628.html
  48. 328LMF-B – SureFire, accessed September 2, 2025, https://www.surefire.com/328lmf-b/
  49. SureFire 628 Handguard Flashlight Patent | PDF | Screw | Shotgun – Scribd, accessed September 2, 2025, https://www.scribd.com/document/848873653/SureFire-628-handguard-flashlight-patent
  50. A brief history with me and Knight’s Armament Company. – Redback One, accessed September 2, 2025, https://redbackone.com/blogs/news/a-brief-history-with-me-and-knights-armament-company
  51. Military CatalOG – Knight’s Armament, accessed September 2, 2025, https://www.knightarmco.com/pdf/military_catalog_2012.pdf
  52. Knight’s Armament MP5 RAS | Rooftop Defense, accessed September 2, 2025, https://www.rooftopdefense.com/product/knights-armament-mp5-ras-new-in-box/
  53. KNIGHT’S ARMAMENT H&K MP5 RAS HANDGUARD – Brownells, accessed September 2, 2025, https://www.brownells.com/gun-parts/rifle-parts/rifle-handguards-parts/hk-mp5-ras-handguard/
  54. Knights Armament Vero Beach H&K MP5 RAS Rail – Wet Worx Outfitters, accessed September 2, 2025, https://wetworxoutfitters.com/knights-armament-company-vero-beach-h-k-mp5-ras-rail/
  55. Knights Armament MP5 RAS Rail Fits H&K MP5 Black -97198 HK New – Other HK Accessories & Parts at GunBroker.com : 1110671265, accessed September 2, 2025, https://www.gunbroker.com/item/1110671265
  56. Canadian Special Forces MP5 RAS Rail for HK MP5 and clones from Cadex, accessed September 2, 2025, https://charliescustomclones.com/canadian-military-mp5-ras-adapter-for-hk-mp5-and-clones/
  57. B&T – Wikipedia, accessed September 2, 2025, https://en.wikipedia.org/wiki/B%26T
  58. History | B&T USA, accessed September 2, 2025, https://bt-usa.com/support/history/
  59. B&T handguard for HK MP5/MP5SD/MP5K, accessed September 2, 2025, https://bt-ag.ch/en/produkt/bt-handguard-for-hk-mp5-mp5sd-mp5k/
  60. B&T HK MP5, SP5, HK94 Lightweight Tri-Rail Handguard – HKPARTS, accessed September 2, 2025, https://hkparts.net/all-parts/b-t-hk-mp5-sp5-hk94-lightweight-tri-rail-handguard/
  61. How a Swiss MP5 Clone Made History: B&T BT96 – YouTube, accessed September 2, 2025, https://www.youtube.com/watch?v=4G-KL_0xYEo
  62. History – Aimpoint US, accessed September 2, 2025, https://aimpoint.us/history/
  63. Red dot sight – Wikipedia, accessed September 2, 2025, https://en.wikipedia.org/wiki/Red_dot_sight
  64. Evolution of the Combat Optic | RECOIL – Recoil Magazine, accessed September 2, 2025, https://www.recoilweb.com/evolution-of-the-combat-optic-135873.html
  65. Military Arms Corporation MAC 5: Best MP5 Clone Available? – Recoil Magazine, accessed September 2, 2025, https://www.recoilweb.com/military-arms-corporation-mac-5-186073.html
  66. MAC 5 MP5 Clone: You Won’t Stop at Just One (Mag, That Is) – YouTube, accessed September 2, 2025, https://www.youtube.com/watch?v=ZsV6Rg-4cnk
  67. Misc. INFO | AK Master Mount, accessed September 2, 2025, https://akmastermount.com/miscinfo/
  68. Not sure about MI side mount. – GunSite South Africa, accessed September 2, 2025, https://www.gunsite.co.za/forums/showthread.php?81247-Not-sure-about-MI-side-mount
  69. Everything You Want to Know About AR Receivers | U.S. Arms Company, accessed September 2, 2025, https://www.usarmsco.com/everything-you-want-to-know-about-ar-receivers/
  70. Budget vs. Premium AR-15 Accessories: Are High-End Products Worth It?, accessed September 2, 2025, https://blackrifledepot.com/blog/budget-vs-premium-ar15-accessories-are-highend-products-worth-it/
  71. Mp5 Retractable Stock – Stanford EdTech Lab, accessed September 2, 2025, https://edtechdev.stanford.edu/mp5-retractable-stock
  72. Magpul MP5: Accessories & Installation | An Official Journal Of The NRA, accessed September 2, 2025, https://www.americanrifleman.org/content/magpul-mp5-accessories-installation/
  73. Magpul Mp5 Stock – Stanford EdTech Lab, accessed September 2, 2025, https://edtechdev.stanford.edu/magpul-mp5-stock
  74. The best upgrades to any MP5. – YouTube, accessed September 2, 2025, https://www.youtube.com/watch?v=9I3UYOuZnSg
  75. Recoil x HK Parts: MAC 5 Buildout Breakdown – HKPARTS, accessed September 2, 2025, https://hkparts.net/blog/recoil-x-hk-parts-mac-5-buildout-breakdown/
  76. The PTR 9CT Modernization Project – YouTube, accessed September 2, 2025, https://www.youtube.com/watch?v=H6aG4Pv6bvw
  77. Midwest Industries MP5 Rails – YouTube, accessed September 2, 2025, https://www.youtube.com/watch?v=uVoiSUqjj-8
  78. H&K MP5 — History and Function – Firearms News, accessed September 2, 2025, https://www.firearmsnews.com/editorial/the-history-and-function-of-the-hk-mp5-parabellum/77889
  79. H&K MP5 Ultimate Guide (+ Current Clones) – Lynx Defense, accessed September 2, 2025, https://lynxdefense.com/hk-mp5-ultimate-guide/
  80. Snagged one of these today : r/guns – Reddit, accessed September 2, 2025, https://www.reddit.com/r/guns/comments/1frvn5n/snagged_one_of_these_today/

What is the history of PTR Industries and the HK91?

It seems like roller-locked firearms are having a resurgence as of late with a number of vendors making them. My first roller lock was from a company that is still around and I actually just bought a MP5 clone from them that I need to write about. Before I do that, let’s review how PTR came into existence.

Timeline

  • Origins (1997-2005): The story begins with Jose Luis Diaz, a Cuban-American entrepreneur with a passion for firearms. In 1997, he established JLD Enterprises in Connecticut, aiming to manufacture American-made versions of the G3 rifle. JLD’s PTR-91 (Precision Tactical Rifle) gained traction among enthusiasts seeking a domestic alternative to imported G3s.
  • Acquisition of FMP Tooling (2003-2005): A pivotal moment occurred when JLD acquired the original tooling and machinery from Fábrica Militar de Braço de Prata (FMP) of Portugal, a licensed manufacturer of H&K G3 rifles. This acquisition included blueprints, gauges, and thousands of parts, granting JLD the capability to produce rifles using the same equipment that produced the original G3s. To be clear, PTR did not license the designs and what not from H&K – they bought them from FMP.
  • Formation of PTR Industries (2006-Present): In 2006, Diaz partnered with P. Everett Weed, an experienced manufacturer, to form PTR 91 Inc. This marked a rebranding and expansion of JLD Enterprises who was folded into PTR. Diaz left in late 2010 and the direction of PTR changed from a focus on assembling firearms from surplus parts to one of new designs and innovation. Currently, PTR has the in-house capabilities to make all of the parts of their firearms.

I really like MP5 and MP5K-type weapons, so let’s add key dates in for them:

  • 2017: PTR Industries first announced their plans to produce MP5 clones at the 2017 SHOT Show.
  • Late 2018 / Early 2019: PTR began shipping their first MP5 clones, the PTR 9CT pistol and the PTR 9KT pistol. These were essentially clones of the HK SP5K, a semi-automatic pistol version of the MP5K.
  • 2020: PTR expanded their MP5 clone lineup with the release of the PTR 9R rifle, a clone of the HK94 carbine.
  • 2021: PTR introduced the 5R rifle, a clone of the HK SP5, a semi-automatic rifle version of the MP5.

Key Individuals

  • Jose Luis Diaz: Was the founder of JLD Enterprises and the visionary behind bringing G3 rifle production to the United States. He left PTR in 2010.
  • P. Everett Weed: Instrumental in the formation of PTR 91 Inc. and the company’s growth through his manufacturing expertise and business acumen.

Conclusion:

PTR Industries has carved out a niche around the family of HK-related roller-locked weapons. Given the continued popularity of those types of firearms, they are well positioned. PTR is working on reselling and perhaps later making weapons such as the Archon B and D pistols and both Jack and Reacher shotguns.

So, PTR continues to evolve. I’ve found their products to be well done in the past and own a 9CT (MP5) currently. It will be interesting to see where the firm heads. I’ve owned a few PTR firearms over the years – a 91 clone, a 7.62x51PDWR and now the 9CT – I have no hesitation in recommending them.


Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.


If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@*********ps.com. Please note that for links to other websites, we are only paid if there is an affiliate program such as Avantlink, Impact, Amazon and eBay and only if you purchase something. If you’d like to directly donate to help fund our continued report, please visit our donations page.


Reviving Old Black Plastic HK Grips – Or Just About Any Other Faded Plastic

Do you have an old HK grip, or any other plastic item, you want to rejuvenate? Or maybe you bought one of the contract grips, washed it and now it’s a dull grey and all of the scratches stand out and you want to make it look better?  It’s easier than you might think.

Clean the grip

I recently boought a bunch of the the surplus HK33 “contract grips” that were made by SME Arms and Ordnance manufacturer, Malaysia under license from HK and most of them really needed cleaning – everything from cosmoline to brown masking tape with numbers were on them.

The first thing is to really clean the grip.  I use a Vevor 30L ultrasonic cleaner [click here for a review I did on mine] with Simple Green HD and water in it but you can use any warm-to-hot soapy water and something to scrub with to clean it up.  Use compressed air to blow it dry real quick before any exposed steel surfaces rust.

These HK33 grips are a mess. Most are beaten up to some extent. Many were covered in cosmoline – that grip on the top that is shiny is coated in it. Some even had old dry masking tape wrapped around the actual hand-grip portion.

For cleaning, I use an ultrasonic cleaner. I have a 30 Liter Vevor and it’s great. Vevor offer all kinds of sizes – if you are interested, click here for a blog post I did about mine. You can calso click here to see the current listings on Amazon.

If you aren’t interested in ultrasonic cleaners, you can also have very good luck with hot soapy water. I used to recommend brake cleaner but that has really lost its cleaning power as various regulations have really reduced its strength.

This is a 30 liter Vevor ultrasonic cleaner filled with Simple Green Pro HD heated to 158F (70C). It gets rid of pretty much everything in 15 minutes including most if not all of the paint in the lettering.

Dealing with scratches and small nicks

Major repairs can be a challenge. Filling them with black epoxy or black super glue creates visible repairs. Black super glue to close a clean crack works surprisingly well. Starbond makes a black super glue that is superb at closing cracks plus bonding clean surfaces together in general – click here to see it at Amazon

For minor scrapes and scratches, the best approach I have found is to use 0000 (sometimes called “quadruple ought” or super fine) steel wool and vigorously rub down surfaces to get rid of scratches and any plastic sticking up from getting nicked. The benefit I have found with it vs. sandpaper is that it doesn’t destroy the surface finish as easily.

This is an actual HK German SEF grip converted for use on an MP5K. I used 0000 steel wool to knock over any sticking out plastic and reduce minor scratches. I find careful use of steel wool helps me improve the surface some without destroying the pebbled finish on the plastic.

Restoring the black color

Black plastic fades as the surface layer loses its oil/moisturizers.  The trick to try and replace those lost chemicals and bring the color back.

Black plastic that has been ultrasonically cleaned is greyish and you can see all of the scratches. If you don’t know it’s coming you can have a “what just happened” moment.

The treatment I use is made by Car Guys and is called “Plastic Restorer”.  Again, make sure the grip is clean and then rub this stuff in.  I use nitrile gloves and work it in.  You want a thin film there.  I let the stuff sit overnight and buff it off with a shop towel the next day.  It does a nice job and will last for sometime.  I’m not exactly sure how long – I’ve been using it for almost six months and nothing has faded yet.

On this HK SEF grip, it’s been cleaned and I used steel wool to knock down any rough spots. Next up is applying Car Guys Plastic Restorer.
The actual cream that comes out is an odd blue grey color. I wear nitrile gloves, put the cream in my glove and then apply enough to leave a film.
It does need to have a light film – not super thick but something like this.
It has to sit to work, I try to let it sit overnight if I can. They say at least 10 minutes but I find the longer the better. You then wipe it down and remove any residue on the surface,
This is the same grip. It sat overnight and then I wiped it down the following day.
Same grip – other side.
These are four of the grey ashen grips shows above after following this process.
Same grips – the other side.

Summary

I did not know why black colored platics fade with time. Now I do and the Car Guys Plastic Restorer works on more colors than just black. Click here for it on Amazon – there’s a reason there are over 31,000 reviews and a score of 4.4. It’s that good. So, whether it’s plastic on firearms, cars or something else, this stuff might really help you bring the color back.

One perk is that it does seal and provide UV protection after it is applied. I’ve been using it for six months and nothing has faded yet but then again, no finish lasts forever so I would bet that some day I will need to touch things up.

Note: This stuff isn’t for headlights and it doesn’t fix physically damaged plastic when there is a thick crust of oxidation or scratches. It’s meant to bring the color back is all.

I hope this helps you out.


Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.


If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@*********ps.com. Please note that for links to other websites, we are only paid if there is an affiliate program such as Avantlink, Impact, Amazon and eBay and only if you purchase something. If you’d like to directly donate to help fund our continued report, please visit our donations page.


How to Convert a Magpul SL Grip For Use On A MP5K

There are some things I like on MP5Ks and some things I don’t.  I usually dislike the triggers but my MKE AP5-P has a fairly decent trigger as MP5 and MP5Ks go.  My MKE also had a factory contoured grip.  Of all the HK grips out there, the contoured is the one I like best but there is one I like even more – the “Magpul SL Grip for HK94, HK93, 91 and Semi Shelf Clones”.  That one heck of a long product name – just remember the model – MAG1070-BLK.

This is the Magpul “SL Grip Module for HK94/93/91/MP5 & Semi Shelf HK Clones” – Model MAG1070-BLK
Zenith ZF5-P. Very nicely made pistol. Relatively bland grip.
Century Imports’ MKE AP5-P. It’s excellent. I like the contour grip more but that’s a personal preference.

A few months ago, I installed one on my Zenith ZF5-P and really liked it.  Whereas the MKE has a contoured grip, the Zenith has a basic straight grip that is only slightly more ergonomic than a rounded rectangle.  I’d read a few posts about guys converting over the Magpul grip, so I did the same.  You know what? I realy like it.

Here it is on the Zenith. By the way, that is Magpul’s cool ESK Extended Selector Lever. I have links to them at the bottom of the post.
Here’s the second one on my MKE AP5-P.

Doing the Conversion

The Magpul SL grip wasn’t designed for use on a MP5K but what you need to do is pretty straight forward if you have the tools and at least some basic knowledge of locating holes to be drilled.

Let’s go over some basics – first off, the steel “tail” that sticks out of the Magpul will need to be cut off.  I’d recommend using something like a hacksaw, reciprocating saw or a bandsaw.  I have a metal cutting bandsaw so I used that. Please notice I did not list a Dremel or similar rotary tool with an abrasive wheel.  They risk making the steel so hot that the plastic could be damaged.

The first step was to cut off the tail. I did it flush with the end of the plastic and cleaned it up with a belt sander.

Next, sand the tail end smooth.  Take off as little material as possible as it will help you get a solid lockup.

Take off as little material as you can until the grip fits and the end cap, brace or stock can fully seat. By the way, I should have cleaned up a bit more before this photo – the dust you see if from me sanding Hungarian Grey-Blue AMD grips that we make. The dust is not from the Magpul grip – it will be black flecks of plastic and a bit of metal from the steel reinforcing channel inside the rear.

As you may have noticed, many MP5K-type weapons, such as those from MKE and Zenith, use two small pins to retain the grip assembly – one in the front at the bottom and one in the top rear.  With the semi shelf and a snug fit, you just need the single rear pin to hold the grip’s rear end up and in place.

The front of the grip has a plate that interfaces with the semi shelf on your MP5K.  Magpul includes instructions for SP5 owners that they may need to remove a little material for a good fit and I would assume this extends to the SP5K but I don’t know this for sure.  With both my MKE and Zenith, no adustment was needed.

That little rectangle welded just to the right of the front grip pin hole is the semi shelf.
This is the locking plate for the grip that interfaces with the semi shelf at the bottom slot in the photo (if the weapon were held upside down, it would be the slot at the top .)

In terms of locating the hole, take your current grip and measure backwards from the front locking plate to the center of the hole.  Then, measure down from the top of the grip.  Use these two measures to locate where you need to do your cutting and then setup your mill accordingly or at least a good drill press because all you are doing is plunge cuts.

Measure the hole from the locking plate to where the center of the hole is on your existing grip – this is the horizontal measure. I’d recommend using calipers to do this. You then need to do the vertical location by measuring from the top of the grip to the center of the existing hole. The more precise you can be, the better your results will be.

Cutting the rear hole. 

Critical: You must make an insert from hard wood, plastic, or aluminum. If you don’t, the walls of the grip will flex and your holes are going to be a mess. I learned this the hard way. The width left to right is about 7/8″ and then you can decide how you want to handle the vertical. I’d recommend surrounding the area where you want to make the cut. I run my insert the whole length of the inside top to provide a firm support both for the clamps and the plunge cuts. You don’t wany anything to flex.
If you don’t have an insert to keep the grip open, they will flex as you attempt to cut them and you’ll make a mess. This is 7/8″ left to right. I then made it the length I wanted. The “leg” on the left bottom is to help it stay in position in the grip. The hole on the right shows you where the 6mm end mill plunges into it.

The first step is to cut the reliefs where the pin goes. The head of the takedown pin is about 9-9.1mm wide. A 9.5mm cut doesn’t give you much room to adjust.  10mm is just a tad wider and gives you more room to adjust your cuts later with a circular file and not have the head unable to sit down in the recess. The reliefs need to be cut about 3mm deep.

That is a 10mm end mill and I just finished a 3mm deep cut. A 9.5mm head would give you a tighter fit around the head of the pin but 10mm gives you some adjustment room.

Next is to cut the 6mm holes for the pins. I’d recommend against a drill bit as it might get squirrely on you – both in terms of deflection or the bit getting caught on one of the holes in the steel reinforcement.  Get a 6mm carbide end mill, make sure your grip is held securely and do a plunge cut.

A 6mm end mill was used to plunge cut the center hole for the pin.
Here is the MKE Pin with an OD head diameter of 9.1mm. The countersink was cut 10mm wide and 3mm deep. This gives a bit more room for adjustments.

If you do use a drill press, check your runout.  If you have more than 0.5mm on one side, you risk cutting to big of a hole.  You want to be somewhere between 6.0 and 6.1mm.  If you go too wide, the retaining wire may not get a good enough hold to keep the pin in place.

Cleaning Up

Use a fine file or diamond abrasive stick to remove all material left over from cutting inside the grip so you have a smooth surface.

It’s time to test fit the grip.  It may go in great all by itself or you may need to adjust it just a tad with a circular file.  I’d recommend a 6mm tapered circular file so you have a lot of control. 

This 6mm tapered Bahco file is great for adjusting holes. Click here to see it on Amazon.
Use a circular file to adjust the grip until it fits. Don’t rush – take off a bit and test, take off a bit and test until it fits. That is the Bahco 6mm file I mentioned earlier. It’s great for this kind of work.

Note, test fitting the grip by itself is one thing.  Doing it with the stock, brace or endcap in place is another.  You may find further adjustments with the circular file are required.  Also, you can make things fit sometimes by moving or tapping the grip or whatever is on the end around.  The sheet metal of the receiver can flex and sometimes it gives you just enough alignment to push the pin on through.  I often tap (not bang) them in with a small hammer with a non-marring head.

You want everything to be snug. You’ll find the front pin doesn’t matter if everything is tight.  If you really want a front pin, you would need to make a custom pin given the width of the Magul’s front lower “ears”.  It would also only be cosmetic because you would be inserting a steel pin into soft plastic that does not have a reinforcing plate. 

The moral of the story is to keep the front-to-back length of the grip long so it is snug – again, don’t cut or sand off more of the black plastic than you must.  Also, try to be as close as you can with the pin holes at least vertically.  Because of how the grip is sandwiched between the mag well and whatever is on the rear, it’s not going anywhere.  The rear pin is the final part to limit movement.

I used the file to slot the hole backward just a bit. Note how tight the grip is up against my SB Tactical brace. It’s not going to wiggle.

The Results

The MKE feels great. I will upgrade the selector the Magpul ESK but even with the stock MKE selector I like the feel more.

Summary

I hope this helps you out if you want to do this yourself.  For folks who just want to do the final filing adjustments, we will converted Magpul grips for sale. Please click here to go to our store.

Here are the original Magpul grips in case you are looking for them:

Production Grip Comment

For our production grips. the holes are based on a new unissued German MP5K grip. Depending on a bunch of factors, the exact holes in the grip you get will vary a bit. Fitting will be required – front to back and the hole locations.



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If you are looking for an extended selector lever for your MP5 or MP5K, these are really nice.

Best MP5/MP5K Upgrade Ever – The Timney MP5 2-Stage Trigger

I hate bad triggers and the worst triggers I have ever used were on HK MP5 and MP5K weapons. I have no idea of the design intent – maybe a real strong emphasis on avoiding an accidental discharge by having a long spongy pull and then a break somewhere around eight pounds. For someone who likes crisp triggers and a lighter pull, the HK triggers in general can be a rude awakening.

I recently picked up Zenith Firearms ZF5-P, which is a MP5K clone. Zenith Firearms is based in Afton, VA, and make their various rifles and pistols there. They used to import MKE clones from Turkey but severed ties and are actually making them here in the US.

I bought the ZF5-P for a few reasons – First, I got a good deal on it. That always helps. Second, I no longer had any form of an MP5 and kind of wanted to get back in. Third, and the subject of this story, I knew Timney made a well-regarded trigger pack for the MP5/MP5K. Fourth, I had an urge to tinker and needed a test platform.

Now Zenith makes a big deal that they machine their cartridge walls vs. bending sheet metal resulting in a better trigger. I was kind of curious to check that out as well.

For the rest of the article, I’ll just refer to the trigger as an MP5 trigger because the MP5 and MP5K share the same trigger pack. It’s the grip that differs.

The Zenith’s Original Trigger

Well, I was hoping for a good trigger out of the box because of Zenith machining the walls of their trigger pack but to be honest, it was just another MP5 trigger. I bought a new Century MKE AP5-P and its trigger was better than the Zenith’s also. It’s not that the Zenith’s trigger is bad – my point is that the unit I received was no better than any other MP5 trigger I’ve used.

I used a Wheeler “Professional Digital Trigger Pull Gauge” and did 10 pulls of the trigger after lubrication plus I had pulled the trigger maybe two dozen times since I bought it so there was a tad bit of wear in before testing. At any rate, the lightest pull was 7 pounds 5.9oz. The heaviest was 7 pounds 13.5 ounces and the average came in at 7 pounds 11.3 ounces. So, just shy of 7.75 or seven and three quarter pounds. Still long, creepy, spongy … pick the bad discriptor you like.

The Timney MP5 2-Stage Trigger

It’s nicely machined and ready to go. You just need to move the ejector, ejector axle and ejector spring from your old trigger to this one. It’s easy to do.

These triggers are compatible with SEF/ Semi-Auto trigger packs and their style of safety selector levers.

These triggers are NOT compatible with Ambi/Navy/FBI trigger packs or .22 clones, as they are different internally.

Timney provides clear installation instructions in the package plus they have the following video to help with the install.

Folks, that trigger is amazing. Here are pull test results: Minimum pull weight was 3 pounds 2.7 oz. Maximum was 4 pounds 0.1 ounce. The average was 3 pounds 10.3 oz.

I’d call it crisp and clean. Night and day better than the original Zenith trigger.

Range Time

My brother-in-law, nephew and I took the Zenith ZF5-P and a Century MKE AP5-P to the range. For an MP5, the MKE’s trigger is fairly decent but was seriously beaten by the Timney.

My nephew really liked the Timney trigger – we all did. By the way, one thing I really like is that a B&T low profile optics mount enables you to cowitness a Vortex Crossfire red dot with the iron sights.

Summary

I have never hid my dislike of MP5 triggers – I genuinely don’t like them and the only good things I can say are that they are reliable and you’ll probably never have an accidental discharge.

The Timney trigger ranks as one of the best upgrades I have done to a firearm. If you want a better trigger for your MP5/MP5K, or a clone of them, then get the Timney trigger.


Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.


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Looking for a hell Of a .308 AR Platform Sniper Rifle? Brownells Has The HK MR762A1 LR Package For $1,000 Off List

Folks, the HK MR762A1 LR is a heck of a rifle. I’ve been tracking them for a while and am always wishing I could afford one for myself. They are consistent sub-MOA rifles and reliable as well. Check out this great MAC review:

What is in the LRP package?

  • Leupold 3-9VX-R Patrol 3-9x40mm Scope and Mount
  • HG G28 Adjustable Cheekpiece Buttstock
  • LaRue Tactical BRM-S Bipod
  • ERGO Pistol Grip
  • Blue Force Gear Sling
  • OTIS cleaning kit
  • One 20 round and one 10 round magazine
  • 1720 Pelican 42″ case

Brownells Has A Deal That Can Save You $1,000

Brownells has the MR762LRPA1 Packages in stock.

Brownells has a good deal going for the MR762LRPA1 package. These LRP packages are not cheap by any means. List is $7,499.99 and Brownells is selling them for $6,499 and they have them in stock. Click here to go there now. Again, they have them in stock as well!

These MR762A1 LR rifles are really something and I sure hope to own one some day.



If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@*********ps.com. Please note that for links to other websites, we are only paid if there is an affiliate program such as Avantlink, Impact, Amazon and eBay and only if you purchase something. If you’d like to directly donate to help fund our continued report, please visit our donations page.