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How to build AK/Kalashnikov-type semi-automatic rifles and pistols.

Section 1: Introduction – Deconstructing the Myth of Soviet “Cosmoline”

For any collector of 20th-century military surplus firearms, the experience is a familiar one: opening a wooden crate or unwrapping a paper-and-oilcloth bundle to reveal a piece of history, entombed in a thick, sticky, amber-to-dark-brown grease. This ubiquitous substance, the bane of many an enthusiast, is the primary barrier between acquiring a historical artifact and rendering it a functional firearm.¹ In the United States and the broader Western world, this preservative is almost universally known by the genericized trademark “Cosmoline.” However, when dealing with arms originating from the former Soviet Union and its client states, this term is a misnomer. The waxy preservative slathered on everything from Mosin-Nagant rifles to SKS carbines and Kalashnikov parts kits is a distinct substance, developed and standardized under a completely different system to meet a unique set of strategic and environmental challenges.

The true subject of this analysis is the primary Soviet-era long-term corrosion inhibitor, known officially as Смазка защитная ПВК (Smázka zashchítnaya PVK), which translates to “Protective Grease PVK”.³ While this is its technical designation, it is far more widely known by its colloquial name:

пушечное сало (pushechnoye salo), or “cannon lard”.³ This evocative nickname is a critical first clue to understanding the material’s context.

The term ‘salo’ holds a deep cultural significance in Russia, Ukraine, and other Slavic nations. It refers to slabs of cured pork fatback, a traditional and enduring food staple, particularly valued for its high energy content and long shelf life.⁶ The preservative’s thick, greasy, and often off-white to yellowish-brown appearance bore a striking resemblance to this familiar food item, leading soldiers and depot workers to adopt the practical and descriptive moniker “cannon lard.”

This act of naming military equipment after a mundane, greasy object is not unique to the Soviet experience. It reveals a fundamental aspect of soldiering culture that transcends ideology and national borders. A striking parallel can be found in the American military’s nickname for the M3 submachine gun. Due to its simple, stamped-metal construction and resemblance to a common mechanic’s tool, the M3 was almost universally dubbed the “Grease Gun”.¹⁰ In both cases—”cannon lard” and “grease gun”—the premier military powers of the Cold War independently arrived at similar colloquialisms rooted in the practical, unglamorous, and greasy realities of their equipment. This is not a mere coincidence; it reflects a shared “grunt-level” perspective, where soldiers relate to the tools of their trade not through official nomenclature but through visceral, descriptive, and often slightly pejorative terms. Understanding this parallel provides a humanizing context for the technical analysis that follows, grounding the chemistry and doctrine in the everyday language of the men who used these weapons.

Section 2: A Comparative Analysis: Soviet ПВК vs. American Cosmoline

To fully understand pushechnoye salo, it is essential to analyze its specific formulation and properties, contrasting them with the American product that has lent its name to the entire category of military preservatives. This comparison reveals two parallel yet distinct technological solutions to the common problem of long-term metal preservation.

The Soviet Standard: ГОСТ 19537-83 and Смазка ПВК

The production and quality of pushechnoye salo were governed by a strict state standard, or ГОСТ (Государственный стандарт). The primary standard for this grease was ГОСТ 19537-83, which superseded earlier versions like ГОСТ 10586-63 and ГОСТ 3005-51.³ GOST standards were mandatory benchmarks in the Soviet Union, ensuring uniformity and quality control across its vast industrial base.

Chemical Composition: According to GOST 19537-83, Смазка ПВК is a carefully formulated compound, not a simple grease. Its primary components are ⁴:

Base: A fusion of петролатум (petrolatum), a semi-solid mixture of hydrocarbons also known as petroleum jelly, and a viscous mineral oil. The specific type of petrolatum used could affect the final color, with some batches appearing light-yellow rather than the more common brown.
Additives: To enhance its protective properties, two key additives were introduced. The first is 5% церезин (ceresin), a refined, hard mineral wax derived from ozokerite, which increases the grease’s melting point and consistency. The second, and more critical, is the corrosion-inhibiting additive МНИ-7 (MNI-7). Technical sources identify MNI-7 as an oxidized ceresin, which improves the grease’s ability to adhere to surfaces and provides active anti-corrosion properties.

Physical Properties: The formulation of ПВК resulted in a set of physical characteristics tailored for the Soviet military’s specific needs ⁴:

Appearance: A thick, highly adhesive, sticky ointment, typically brown in color.
Thermal Behavior: The grease has a relatively low melting point, beginning to soften and flow at temperatures above 50°C (122°F). This property is crucial for its application, which was typically done by dipping heated parts into a molten vat of the grease. The MNI-7 additive was particularly important for improving its thixotropic properties, helping it to cling to vertical surfaces without slumping off entirely.
Cold Weather Performance: This is arguably the most critical feature of ПВК. While the grease becomes extremely thick and loses all mobility below 10°C (50°F), making cold application nearly impossible, it crucially retains its protective, corrosion-inhibiting film integrity down to -50°C (-58°F). At these extreme temperatures, it does not crack or flake away, ensuring the metal beneath remains sealed.
Water Resistance: Like all hydrocarbon-based greases, ПВК is completely insoluble in water. Its formulation provides exceptionally high water resistance, physically blocking moisture from reaching the metal surface, which is the cornerstone of its preservative capability.

The American Counterpart: MIL-C-11796C and Cosmoline

The substance known as Cosmoline has its own distinct history and specifications. It was originally developed by the chemical company Houghton International in the 1860s or 1870s, not as a rust preventive, but as a pharmaceutical product. It was used as a versatile ointment for everything from disinfecting wounds and treating veterinary ailments to promoting hair growth.¹² Its transition to military use occurred when it received a government specification as a rust preventive, and it was subsequently used to protect equipment from the Spanish-American War through the Vietnam War.¹²

The modern standard for this type of preservative is U.S. Military Specification MIL-C-11796C, Class 3.

Chemical Composition: Chemically, Cosmoline is described as a homogenous mixture of oily and waxy long-chain, non-polar hydrocarbons. Its primary ingredient is a volatile aliphatic petroleum solvent.¹² This solvent keeps the compound in a viscous, grease-like state when fresh but is designed to slowly evaporate over time, leaving behind the more solid, waxy hydrocarbon protective layer.

Physical Properties:

Appearance: Cosmoline is consistently brown in color, though its viscosity can vary.¹²
Thermal Behavior: It has a melting point of 45–52°C (113–126°F), remarkably similar to its Soviet counterpart, ПВК. Its flash point is 185°C (365°F).¹² This similar melting range indicates that both the US and Soviet militaries arrived at a similar thermal window for a grease that was stable in most ambient conditions but could be easily liquefied with moderate heat for application and removal.

Table 1: Comparative Properties of Soviet ПВК vs. American Cosmoline

Property	Soviet Смазка ПВК	American Cosmoline
Official Designation	Смазка защитная ПВК (Protective Grease PVK)	Preservative and Sealing Compound
Governing Standard	ГОСТ 19537-83 ³	MIL-C-11796C, Class 3 ¹²
Colloquial Name	пушечное сало (Cannon Lard) ³	Cosmoline ¹²
Primary Chemical Base	Petrolatum and viscous mineral oil ⁴	Long-chain, non-polar hydrocarbons ¹²
Key Additives	Ceresin (mineral wax), MNI-7 (oxidized ceresin) ⁴	Aliphatic petroleum solvent (volatile) ¹²
Color	Brown or light-yellow ⁴	Brown ¹²
Melting Point	>50°C (122°F) ⁴	45–52°C (113–126°F) ¹²
Effective Low-Temp Range	Protects down to -50°C (-58°F) ⁴	Not specified, but used in global conflicts
Primary Application	Hot-dip immersion	Hot-dip, brushing, or spraying

Section 3: The Doctrine of Preservation: Why the Red Army Greased Everything

The ubiquitous presence of pushechnoye salo on Soviet-bloc military hardware was not a matter of simple maintenance preference. It was the direct, tangible result of a deeply ingrained military doctrine shaped by geography, history, and the existential threat of the Cold War. The grease itself is an artifact of a strategic philosophy that prioritized mass, endurance, and readiness for a conflict of unimaginable scale.

Strategic Depth and Long-Term Storage

Soviet military doctrine during the Cold War was fundamentally oriented toward preparing for a massive, protracted, and highly attritional ground war against the combined forces of NATO.¹⁵ This was not a strategy built around short, decisive conflicts, but one that anticipated a continent-spanning struggle that would require the total mobilization of the state’s resources over a long period. This doctrine of “deep operation” and continuous combat necessitated the production and storage of immense quantities of military materiel. For every tank, rifle, and artillery piece in active service, there were many more held in strategic reserve, ready to equip wave after wave of mobilized divisions.¹⁸

This created a colossal logistical challenge: millions of weapons, vehicles, and spare parts had to be preserved in a state of readiness for years, or even decades, awaiting the call to war. The primary enemy during this long wait was not a foreign power, but the slow, relentless process of corrosion. A rifle that has rusted in a depot is as useless as one destroyed in battle. Therefore, a cheap, effective, and reliable long-term preservative was not just a convenience; it was a cornerstone of Soviet strategic readiness.

Warfare in a Harsh Climate

The physical properties of Смазка ПВК were meticulously tailored to the geographic and environmental realities of the Soviet Union and its likely theaters of war. The operational landscape stretched from the humid shores of the Black Sea to the frozen tundra of the Arctic Circle. The disastrous experience of the German Wehrmacht during Operation Barbarossa served as a powerful, enduring lesson for Soviet planners. In the winter of 1941, standard German lubricants for everything from machine guns to tank engines froze solid, crippling their war machine at the gates of Moscow.¹⁹

The Soviets learned this lesson intimately. The specification that ПВК must maintain its protective integrity without cracking or flaking at temperatures down to -50°C (-58°F) was a direct response to this historical reality.⁴ It was a critical design requirement, ensuring that weapons pulled from a frozen Siberian depot would be protected from corrosion until they could be de-preserved and issued. This institutional focus on extreme cold-weather operations was evident in many areas of Soviet practice, such as the field-expedient technique of thinning engine oil with gasoline to start tanks and aircraft in sub-zero temperatures.²⁰

A System, Not a Substance: The ЕСЗКС

It is crucial to understand that Смазка ПВК did not exist in a vacuum. It was one component within a vast, highly structured, and state-mandated framework known as the ЕСЗКС (Единая система защиты от коррозии и старения), or the “Unified System of Corrosion and Ageing Protection”.²¹ This system, codified in a library of interlocking GOST standards, governed every aspect of material preservation for the entire Soviet state, from military hardware to industrial machinery.

The existence of numerous related standards, such as ГОСТ 9.054-75, which detailed the accelerated testing methods for preservative oils and greases, and ГОСТ 10877-76, which specified a different type of preservative oil known as К-17, demonstrates the system’s depth and complexity.²¹ The ЕСЗКС prescribed specific types of oils, greases, inhibited papers, and polymer films for different metals, alloys, and storage conditions. It was a holistic, centrally planned approach to defeating material degradation.

This systemic approach reveals the true significance of preservation in Soviet strategic thought. The development and rigid standardization of materials like ПВК were not mundane maintenance tasks. They were a direct expression of a military doctrine predicated on winning a long war through industrial endurance and the overwhelming force of mobilized reserves. In this context, the ability to store millions of rifles for fifty years in perfect condition was as vital to national defense as the ability to manufacture new tanks. The thick, stubborn grease found on a surplus Mosin-Nagant today is, therefore, more than just gunk; it is a physical remnant of Cold War strategic planning, a monument to a philosophy that equated preservation with power.

Section 4: The Aging Process: From Viscous Grease to Hardened Shell

The effectiveness of preservatives like Смазка ПВК and Cosmoline is finite. Over decades of storage, their physical and chemical properties change, transforming them from a pliable grease into the hardened, waxy shell that collectors know well. This aging process was an understood and accepted part of long-term storage doctrine.

Mechanisms of Aging: Evaporation and Oxidation

The hardening of these preservatives is primarily driven by two chemical processes:

Solvent Evaporation: American Cosmoline, in particular, is formulated with a volatile aliphatic petroleum solvent.¹² This solvent is designed to keep the preservative in a viscous, easily applicable state. Over time, especially with exposure to air, these volatile organic compounds (VOCs) evaporate.¹² As the solvent fraction dissipates, what remains is the much harder, wax-like hydrocarbon base, which solidifies on the metal’s surface.¹² This process can begin within a few years of air exposure.¹²
Oxidation: All petroleum-based lubricants, including the base oils in ПВК and Cosmoline, are susceptible to oxidation—a chemical reaction with atmospheric oxygen.⁵⁰ This process is accelerated by heat and the presence of metal contaminants, which act as catalysts.⁵⁰ Oxidation breaks down the lubricant’s base oil and depletes its protective additives, leading to an increase in viscosity, the formation of organic acids, and eventually sludge and varnish.⁵¹ While both preservatives contain antioxidant additives to slow this process, over many decades, oxidation contributes to the overall hardening and degradation of the protective film.⁵⁰

Intended Lifespan and the Reality of Strategic Reserves

Soviet military planners, operating under a doctrine of preparing for a prolonged, attritional war, intended for their equipment to be preserved for many decades.⁵³ The goal was not a commercial shelf life of a few years, but a strategic one that could last indefinitely until the materiel was needed.⁵³ Evidence from recent conflicts, where Russia has pulled tanks and artillery from storage that date back to the 1960s, ’50s, or even ’40s, confirms that the intended preservation period was at least 50 to 80 years.⁵⁵

While modern commercial rust preventatives often list a shelf life of 2 to 5 years, this is a guarantee for optimal performance under specified conditions.⁵⁶ The actual effective lifespan of military-grade preservatives, especially when hermetically sealed away from open air, is vastly longer.¹² The Soviets understood that the grease would age and harden, but this was an acceptable trade-off for multi-decade corrosion protection.⁵³

The Challenge of Hardened Preservative: Then vs. Now

The difficulty of removing these preservatives is directly related to their age and storage conditions. This creates a significant difference between the original Raskonservatsiya process and the task facing a modern collector.

Ideal Timeframe (Fresh Application): When freshly applied or removed from sealed storage, both ПВК and Cosmoline are in their intended viscous, grease-like state. In this condition, the preservative can be largely removed by simply wiping it off with a rag, with minimal need for aggressive solvents.¹² This is the scenario for which the simple Soviet field protocol was designed.
Modern Challenge (Aged Application): After decades of exposure to air, the preservative has solidified into a hard, waxy varnish.¹² This hardened shell does not wipe off easily and is resistant to simple manual cleaning. It requires laborious scraping or, more effectively, the application of heat to melt the wax and chemical solvents to dissolve the hardened hydrocarbons.¹² This is why modern removal methods involving heat guns, boiling water, solvents, and ultrasonic cleaners are not just for convenience—they are a necessity to overcome the chemical changes the preservative has undergone over 50+ years.

Section 5: The Official Soviet Method: Расконсервация per GOST 9.014-78

Just as the application of preservatives was rigidly standardized, so too was their removal. The official process, known as Расконсервация (Raskonservatsiya)—literally “de-preservation” or “de-mothballing”—was designed for simplicity, scalability, and execution by conscript soldiers with minimal specialized equipment. The general requirements for this process were laid out in the overarching standard ГОСТ 9.014-78, “Temporary corrosion protection of products. General requirements”.²⁴

Reconstructing the Official Protocol

By analyzing ГОСТ 9.014-78 and related Russian-language military and technical manuals, the official field-level procedure for bringing a preserved weapon into service can be reconstructed. It was a pragmatic, multi-step process:

Step 1: Mechanical Removal. The first and most intuitive step was the bulk removal of the preservative. Soldiers would use dry, clean rags (ветошью) or soft paper to wipe off as much of the thick, external layer of ПВК as possible.²⁸ This removed the majority of the material without the use of any chemicals.
Step 2: Solvent Application. For the thick, hardened grease that remained, especially in crevices and internal mechanisms, the use of a solvent was prescribed. The most commonly cited and widely available solvent for this task in the Soviet military was керосин (kerosene).²⁹ The procedure did not typically involve soaking the entire weapon. Instead, a rag would be moistened with kerosene and used to wipe down the remaining preservative, dissolving it for easy removal.
Step 3: Degreasing and Final Wiping. After the preservative was fully removed, the surfaces were wiped down with a degreasing agent (обезжиривателем) if available, and then thoroughly wiped with a clean, dry cloth to remove any solvent residue.²⁸ This step was critical to ensure the surface was clean and dry before re-lubrication.
Step 4: Re-lubrication. The final and most important step was the immediate application of a thin layer of standard-issue neutral gun oil (нейтрального оружейного масла).²⁸ A surface freshly stripped of its heavy preservative by solvents is highly susceptible to flash rusting, so this re-application of a light, protective oil film was essential to prepare the weapon for service and protect it from short-term corrosion.

The Doctrine of “Good Enough” in Practice

The striking feature of the official Raskonservatsiya protocol is its sheer simplicity. It eschews complex chemicals, specialized heating apparatus, or electricity-dependent tools. This was not an oversight but a deliberate and intelligent design choice, reflecting a core tenet of Soviet operational philosophy: dostatochno, or sufficiency. The system was not designed to be the most elegant, the fastest, or the most forensically perfect method possible. It was designed to be the most robust, reliable, and effective method for the specific context of the Soviet military.

In a mass mobilization scenario, a procedure requiring sophisticated technology would be a logistical bottleneck and a critical point of failure. A process based on rags, kerosene, and elbow grease, however, is almost infinitely scalable. It could be performed by millions of conscripts with minimal training, in depots, rail yards, or forward assembly areas, using commonly available materials.³² The official Soviet method was the epitome of pragmatism—a “good enough” solution that guaranteed that a preserved rifle could be made ready for battle, anywhere, anytime.

Section 6: The Modern Armorer’s Guide: Top 5 Removal Methods Evaluated

While the official Soviet method was effective for its time and purpose, the modern firearms collector has access to a wider array of tools and chemicals that can make the process of Raskonservatsiya faster, easier, and more thorough. The following analysis evaluates the top five modern methods, including the heated ultrasonic technique, providing a practical guide for today’s enthusiast.

General Principles for All Methods

Before undertaking any removal process, several universal principles should be observed to ensure safety and effectiveness:

Full Disassembly: For a thorough cleaning, the firearm must be completely disassembled. This allows access to all surfaces, including the bore, chamber, bolt internals, trigger group, and small pins and springs where preservative can hide and cause malfunctions.³³
Safety First: The work area must be well-ventilated, especially when using volatile solvents. Appropriate personal protective equipment (PPE), such as nitrile or other chemical-resistant gloves, is essential. When using flammable solvents like mineral spirits or kerosene, all ignition sources must be eliminated.³³
Proper Waste Disposal: The removed grease and solvent mixture is considered hazardous waste. It should never be poured down a drain or onto the ground. It will solidify and cause blockages, and it contaminates the environment. It should be collected and disposed of in accordance with local regulations for hazardous materials.¹²

Method 1: Heated Ultrasonic Cleaning

This method, employed by the user who initiated this query, combines heat, water, a degreasing agent, and high-frequency sound waves to achieve a deep clean.

Procedure: Disassembled metal parts are placed in the wire basket of an ultrasonic cleaner. The tank is filled with hot water and a water-based degreasing solution. Common choices include Simple Green, Zep Citrus Degreaser, or specialized gun cleaning concentrates like those from Hornady or Lyman.³⁴ A dilution ratio of 1 part degreaser to 5 or 10 parts water is typical.³⁴ The unit’s heater is engaged, and the ultrasonic transducer is run for several cycles (e.g., 5-15 minutes each), with parts being rearranged between cycles. The heat melts the
ПВК, while the ultrasonic cavitation creates microscopic bubbles that implode on the part’s surface, scrubbing away the liquefied grease from every corner, thread, and crevice. After cleaning, parts must be immediately and thoroughly rinsed with hot water, dried completely (compressed air is ideal), and coated with a water-displacing oil (like WD-40 or Brownell’s Water Displacing Oil) or a standard gun oil to prevent rapid flash rusting.³⁴
Analysis: This is arguably the most effective, efficient, and thorough method for cleaning metal parts. Its ability to penetrate and clean internal channels, such as firing pin holes and gas ports, is unmatched by manual methods.³⁴ It is a validation of the user’s preferred technique.
Caveats: This method requires a significant upfront investment in an ultrasonic cleaner of sufficient size and power; small, underpowered jewelry cleaners are not suitable.³⁴ It is not safe for wood or most polymer parts. While generally safe for durable military finishes like bluing and parkerizing, there is some anecdotal concern that overly aggressive chemical solutions or excessive cleaning times could potentially harm delicate or worn finishes.³⁷

Method 2: Solvent Immersion

This is a classic and highly effective chemical approach to dissolving the preservative.

Procedure: Disassembled metal parts are fully submerged in a bath of a suitable petroleum-based solvent. The most highly recommended and effective solvents are mineral spirits and kerosene.¹ Diesel fuel and even gasoline have been used, but their high flammability and noxious fumes make them significantly more hazardous.³⁹ For long parts like barrels and receivers, a popular and efficient setup involves using a section of PVC pipe, capped at one end and filled with solvent.¹ After a period of soaking, parts are removed and scrubbed with nylon brushes to remove the softened grease. Because solvents strip all oils from the metal, a thorough post-cleaning lubrication is absolutely critical.
Analysis: An extremely effective method that chemically breaks down the preservative. It is less expensive in terms of initial equipment cost compared to ultrasonic cleaning.
Caveats: This method involves the use of flammable and volatile chemicals, requiring extreme care regarding ventilation and ignition sources. It generates a significant volume of liquid hazardous waste that must be disposed of properly. The process is inherently messy.

Method 3: Thermal Application (Non-Immersion)

This method relies on heat to melt the preservative without submerging the parts in a liquid.

Procedure: This technique varies for metal and wood.

For Metal Parts: A heat gun on a low setting or a standard hair dryer can be used to gently and evenly heat disassembled parts, causing the grease to liquefy and drip off onto a collection surface like a cardboard box or aluminum foil.³³ Some users place parts on wire racks in an oven set to a low temperature (e.g., 200-250°F or ~95-120°C), with a drip pan below.⁴⁰
For Wood Stocks: This is the premier method for removing the grease that has soaked deep into the wood grain. The stock is wrapped in absorbent material like paper towels or brown paper bags, then placed inside a black plastic trash bag. This assembly is then left in a hot environment, such as the dashboard of a car on a sunny day, or inside a homemade “hot box” constructed from a metal trash can and a low-wattage incandescent light bulb.¹ The heat causes the grease to “sweat” out of the wood, where it is absorbed by the paper. The process is repeated with fresh paper until the wood no longer sweats grease.

Analysis: An excellent, low-cost method for removing the bulk of the preservative with minimal use of chemicals. It is the safest and most effective method for cleaning original wood stocks without damaging them.
Caveats: Poses a fire risk if parts are overheated with a heat gun or in an oven. Wood can be scorched or damaged if the heat is too intense or applied unevenly.³² The process can be slow and messy.

Method 4: Aqueous Immersion (Boiling Water)

This method uses the heat of boiling water to melt and separate the preservative.

Procedure: Disassembled metal parts are placed in a large pot or tray (a metal wallpaper tray or a section of rain gutter works well for long parts) and covered with boiling water.³² The heat melts the
ПВК, which, being less dense than water, floats to the surface where it can be skimmed off. Adding a small amount of dish soap can help emulsify the grease. After removal from the water, the residual heat of the metal parts causes the water to evaporate very quickly, aiding in the drying process.
Analysis: This is a very low-cost, effective, and non-toxic method. It uses readily available materials and avoids flammable solvents.
Caveats: This method is only suitable for metal parts that can be safely submerged in boiling water. There is an obvious risk of burns from the hot water and steam. Immediate and thorough drying and oiling are absolutely critical, as the bare, hot, wet steel will begin to flash rust almost instantly upon exposure to air.

Method 5: Manual Cleaning with Modern Degreasers

This is the most direct, hands-on approach, relying on “elbow grease” and modern cleaning agents.

Procedure: This method involves physically scrubbing the preservative off using shop rags, nylon brushes, toothbrushes, Q-tips, and pipe cleaners, aided by a spray-on cleaning agent. A wide variety of products have been used successfully, including citrus-based degreasers, Simple Green, Dawn Powerwash foam, and even foaming bathroom cleaners like Scrubbing Bubbles.³² Some users employ harsher chemicals like brake cleaner, but this must be done with caution.⁴⁰ The process is one of spraying, scrubbing, wiping, and repeating until the part is clean.
Analysis: This method requires the least specialized equipment and is well-suited for firearms with only a light coating of preservative or for targeted touch-up cleaning after an immersion method.
Caveats: It is by far the most labor-intensive and time-consuming method.¹ It is difficult to achieve the same level of thoroughness in hard-to-reach areas compared to immersion techniques. Harsher chemicals like brake cleaner can damage wood, plastics, and some painted or delicate metal finishes.⁴⁰

Table 2: Ranking of Modern Removal Methods

Method	Effectiveness	Safety	Cost (Initial)	Speed	Primary Application
Heated Ultrasonic Cleaning	5/5	4/5	1/5	5/5	Metal Parts
Solvent Immersion	5/5	2/5	3/5	4/5	Metal Parts
Thermal Application	4/5	3/5	4/5	2/5	Metal & Wood
Aqueous Immersion (Boiling)	4/5	3/5	5/5	3/5	Metal Parts
Manual Degreasing	3/5	4/5	5/5	1/5	Metal & Wood (Light)
Ratings are on a 1-5 scale, where 5 is highest/best.

Section 7: Conclusion and Recommendations

This analysis has deconstructed the substance colloquially known as “Cosmoline” in the context of Soviet-bloc firearms, identifying it correctly and placing it within its proper historical, chemical, and doctrinal framework. The investigation yields several key conclusions for the collector and historian.

Summary of Findings:

The primary long-term preservative used by the Soviet military was not Cosmoline, but a distinct substance designated Смазка ПВК, governed by ГОСТ 19537-83. Known colloquially as pushechnoye salo (“cannon lard”), it is a petrolatum-based grease fortified with ceresin wax and an oxidized ceresin corrosion inhibitor.
The development and widespread use of this specific preservative was a direct consequence of Soviet military doctrine. This doctrine anticipated a protracted, large-scale war, necessitating the long-term strategic storage of millions of weapons. The preservative’s exceptional performance in extreme cold was a critical requirement born from the harsh geography of the USSR and the hard-learned lessons of the Second World War.
Over decades, these preservatives age and harden due to the evaporation of volatile solvents and chemical oxidation. This hardening process is why modern, aggressive cleaning methods are necessary, as the original, simple field-cleaning protocols are insufficient for the solidified material found on surplus firearms today.¹²
The official Soviet removal procedure, Raskonservatsiya, was a model of pragmatic simplicity, designed for execution by conscript soldiers using common materials like rags and kerosene. Modern collectors, however, have access to a variety of more advanced and thorough techniques.

Final Verdict on the “Best” Method:

For the serious collector or armorer seeking the most thorough and efficient cleaning of disassembled metal firearm components, heated ultrasonic cleaning represents the current pinnacle of technology and effectiveness. It offers unparalleled deep-cleaning capabilities, especially for intricate parts and internal channels, validating the method preferred by the user who prompted this report.

However, no single method is universally perfect for all parts of a firearm. Therefore, the optimal strategy is often a hybrid approach:

Use the Thermal Application method (e.g., the “sun and black bag” technique) to safely sweat the preservative out of the wooden stock and handguards.
Use Heated Ultrasonic Cleaning for all disassembled metal parts to achieve a forensically clean state.
Follow up with a meticulous manual inspection and touch-up, immediate and thorough drying, and a proper application of high-quality gun oil to all metal surfaces.

This combined methodology leverages the strengths of each technique, ensuring that a historical artifact is not only cleaned but properly conserved for its next chapter of life in the hands of a collector.

Glossary of Key Russian Terms

Смазка ПВК (Smázka PVK): “Protective Grease PVK.” The official designation for the primary Soviet long-term firearms preservative.
пушечное сало (pushechnoye salo): “Cannon Lard.” The widespread colloquial name for Смазка ПВК.
ГОСТ (GOST): Государственный стандарт or “State Standard.” The system of mandatory technical standards in the Soviet Union.
ЕСЗКС (YeSZKS): Единая система защиты от коррозии и старения or “Unified System of Corrosion and Ageing Protection.” The comprehensive state-level system for material preservation.
Расконсервация (Raskonservatsiya): “De-preservation” or “De-mothballing.” The process of removing preservative grease to make equipment ready for service.
керосин (kerosín): Kerosene. The standard field solvent used for Raskonservatsiya.

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Works cited

How to Properly Remove Cosmoline from Military Surplus Firearms – Schafco, accessed July 30, 2025, https://www.originalcosmoline.com/shop/how-to-properly-remove-cosmoline-from-military-surplus-firearms/
Gooey Gat Gunk Bustin’ Cosmoline Removal 101! [Guide] – YouTube, accessed July 30, 2025, https://www.youtube.com/watch?v=rK1xoB1HzeQ
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AK & Related Rifles, AKBuilds, Serbia

How to add an AR stock to a Zastava M77

April 24, 2024 RoninsGrips

Okay, some guys hate AR gear on AKs and if it’s not your cup of tea, that’s fine. I do like AR stocks and have no problems putting whatever stock on whatever family of firearms. I’m more into pragmatism and making a firearms do what I want than arguing over AR vs. AK or whatever. This is also why I have commenting turned off on the blog.

At any rate, even before I bought the M77, I knew I was going to trick it out for my purposes and I wanted to put one of the Magpul PRS Lite stocks on it for a few reasons:

I like adjustable stocks like the PRS but don’t need to constantly change the length of pull or the comb (where your cheek sets) thus I didn’t need to spend the money on a full blown PRS Gen 3. By the way, in case you are wondering PRS stands for “Precision Rifle/Sniper”.
The M77 will never be mistaken for a carbine given its length nor do I need to collapse the stock so the fixed postion PRS Lite was fine by me.
There are aftermarket thick recoil pads you can put on a PRS to absorb recoil.
By using a buffer tube, I can slide in a mercury recoil suppressor to add weight, absorb some of the recoil and balance the rifle out a bit more to compensate for a long barrel and relatively heavy front end.
Last but not least, the PRS Lite reminds me a bit of a PKM stock due to the skeletonized opening. (I’m sure someone just spit their drink out reading that). I had a new mint Romanian PKM stock many years ago that I sold at some point and still wish I hadn’t. In short, I like the looks.
Also, the PRS Lite is a bit cheaper than a PRS Gen 3 but that wasn’t a big factor for me – the PKM look is actually what tipped me in the direction of the Lite model.

This is the MagPul PRS Lite. It’s definitely a solid stock that I like – it does what I need it to.

Parts you will need

Zastava/Yugo to M4 adapter – this screws into the square hole in the rear trunnion and then presents the hole the buffer tube screws into and the end plate. Go with an aluminum model from a reputable vendor like Ace, JMac Customs, Desert Fox, etc. Note, JMac went a very different route with their pioneering 1913 Picatinny rail interface for the stocks and I provide more details down during installation.
A buffer tube – I’d recommend a M4 six position Mil-Spec carbine buffer tube for the greatest flexibility. Rifle length tubes are rarely used on new firearms now as people want the adjustable stocks. Commercial sized buffer tubes were due to some things Colt did many years ago and thus on the way out so go with Mil-Spec which refers to the outer diameter of the tube.
An AR end plate – on an AR, this plate keeps the selector spring captured and also aligns the buffer tube via vertical key that sticks up and keeps the carbine buffer tube from rotating – it does help to have it for that reason and you have tons of options out there ranging from the basic to ones with sling hooks and even QD sling sockets. Not all adapter support an end plate so this might not be needed,
A castle nut – this nut is threaded on the buffer tube and then tightened down against the end plate to secure the buffer tube in place. Note, you will need a spanner wrench or specialized castle nut wrench of install or remove a castle nut without tearing it up – I recommend the Magpul wrench. By the way, the castle nut gets its name from looking like a medevial castle’s crennelated tower. Crenels are the parts that stick up like teeth to give defenders some protection.
Finally, whatever stock you want. Just remember to match the buffer tube to the stock. If you get a rifle stock and it needs a rifle buffer tube then get a rifle buffer tube, etc. The PRS and PRS lite have an adapter and can work with either tube type but most stocks designed for a carbine can only work with a carbine buffer tube (just make sure you match on either the Mil-Spec or commercial diameter).

Removing the old stock

The first step is to remove the recoil pad which is held in place by two beefy wood screws with allen/hex wrench sockets in them. Remove them and then the recoil pad will pull off. You then remove the buttstock bolt and the stock pulls out of the end of the rifle.

Remove these two beefy screws and the recoil pad will pull off. I’m happy to see a modern screw head vs. slotted. I would have been even happier if they were torx screws this is a nice upgrade from the old days.

I kind of felt like Crocodile Dundee when I first saw the new recoil pad screws they are using “Now this is a screw”. If you’ve not seen the movie then the reference is lost but my point is that is a really heavy duty screw.

With the recoil pad off, use a 13mm socket on an extension to reach in and unscrew the buttstock bolt. Yes, that’s a bed. It was super cold out and I set up in our spare bedroom to take these photos.

They’ve shortened the buttstock bolt considerably. I’ve considered having these made but Zastava USA seems to keep them in stock so there is no pressing demand for them unlike our original Yugo military length bolts.

This is what goes into the rear trunnion. The numbering reflects the rifle it was fitted to. Note, these do sometimes get a wee bit stuck in the trunnion so you might need to wiggle it a bit or a few light taps with a rubber mallet and it will pull right out.

This is the rear trunnion and the use of a square hole and big bolt to secure it is one of the unique design changes the Yugoslavs did to the Soviet designs. See the finish residue and chips in there? The snug fitting of the stock, how much the finish has stuck to the metal and a bit of sawdust all combine to cause the stock to offer a bit of resistance during removal. In this case it all came out easily with just a bit of wiggling. You should remove all of that of course.

Adding the new stock

To add the buffer tube, I decided to use two parts that I happened to have in stock. I used an Ace modular adapter (“AKRBY-AR15” is the exact model) and then a JMAC modular stock to M4 adapter that has sadly been discontinued – I bought mine a few years ago so it’s not surprising things have changed.

JMac went a different route some years back and pioneered adapters that expose a 1913 Picatinny rail at the rear to which you can mount a ton of different stocks. That’s another option for you – click here. Once you have that, you add a folding mechanism, then a skeletonized tube (ST) for a cool “I’m not a normal AR look” and then your AR stock if you go that route.

Many, many years ago, Ace Riflestocks was its own company and alos quite a few years back they were acquired by Doublestar Corp – a large AR manufacturer. Same products and quality but you now see a Doublestar logo. Note, there is an Ace to M4 adapter that I have used many times but does not support the end plate. Not the end of the world but a different approach.

If you do not want the modular approach, Zastava also sells a direct adapter. It screws into the rear trunnion and gives you the mount for the M4 buffer tube.

This is the Ace Zastava/Yugo modular stock adapter. Only one of the two rows of screws holes are actually used giving you a bit of vertical adjustment. The adapter is secured by an 8mm allen key socket screw. The screw holes are tapped for #10-32 screws.

The JMac M4-Ace adapter is really well made. The two horizontal screw holes are for securing the Mac Adapter to the modular stock adapter. The bottom opening is for securing the botttom of the AR end plate that in turn holds the buffer tube in position vertically.

Put medium strength Loc-tite on before you install the screws.

If you want to insert a mercury recoil reducer

This next step is entirely optional – I installed a C&H mercury reducer to add weight to the rear and absorb a bit of recoil. The completely sealed 7/8″x5″ C&H tube weighs 16oz. The liquid mercury inside sloshes inside and absorbs some of the recoil. Does it do a ton on it’s own – no. Does it and the weight help mitigate some of the recoil? The short answer is yes.

What I do is wrap tape around the C&H so it fits snug and is roughly centered. I spray brake cleaner in the tub to get any oil out. scuff it up and spray it out again. I then scuff up the C&H tube, clean it with alchol (brake cleaner makes the tape gooey), coat the C&B unit with epoxy and push it in. Some epoxy will come out the drain hole so wipe it off with a rag with brake cleaner and then close it with a piece of tape. By the way, one end of the tube is tapped for a 1/4-20 bolt to help install it. Remove the bolt before everything sets up of course.

That’s not coming out or loosen up. Use a towel with brake cleaner to remove any epoxy on surfaces you don’t want. You need to do this before it sets up. By the way, the longer an epoxy takes to cure, the better it will hold up to shocks over time. Don’t use epoxies that claim to set in just 90 seconds or 5 minutes.

Let’s continue with installing the buffer tube

Put the castle nut on the buffer tubes with the largest slots facing backwards and thread it all the way to the bak, Then install the end plate with the “boss” (raised oval) facing forwards to it will go into the end of the AR adapter. You then insert the buffer tube into the adapter and start screwing it in place. When you can’t screw it in any further because of the plate, back it off a turn, push the plate into the adapter, tighten the castle nut with your fingers. Finally, tighten it down with the caste nut wrench – the torque spec is 38-39 ft pounds (you’ll sometimes ready 40 ft pounds but 38-39 is per USMC TM 05538/10012-IN). If you want to do farmer tight, that is up to you. I’d also recommend staking the nut – putting a divot in the nut in one of the small holes between the end nut and the castle nut so the castle nut can no longer turn without a wrench. Again, up to you.

Here you can see the end plate, the groove in the buffer tube that it travels in and just a bit of the castle nut behind. All are oriented correctly.

I screwed in the buffer tube until the end plate couldn’t rotate, backed it off one turn (or so) until I could get the end plate to slide forward and go in its hole. Note the orientation of the castle nut and it is not tight yet.,

Do you mess with castle nuts a lot? Get a Magpul Armorer’s Wrench. In the photo, the right side is for the castle nut. The left is for the barrel nuts and I don’t use that one much but that castle nut portion gives you a wonderfully secure grip especially when you are breaking ones free. The square hole is for a 1/2″ torque wrench. The oval hole is for rifle receiver extensions and the groove in the castle nut end can be used on the traditional bird cage flash hiders.

Once the buffer is installed, the PRS site can go right on. Just follow the directions with the stock, You remove the screw that holds the front flush cup in place and slide the stock on. You can then put the QD swivel flush cup on whatever side you want.

Both the full blow PRS Gen 3 and PRS Lite stocks have thin hard recoil pads that I always replace. This is a Limbsaver PRS Gen 3 recoil pad that fits both models. It’s well made, fits and feels great. I always make the swap unless the stock is going on a light recoiling rifle like 5.56 NATO. If you want the best recoil pad I have found for the PRS Gen 3 or PRS Lite, get the Limbsaver pad.

End Result

The rifle feels really good and handles well. I think it looks great also!

Summary

Once you know the parts you need, it’s a pretty easy swap to make. Once you get the M4 buffer tube installed you have tons and tons of options out there .

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.

AK & Related Rifles, AKBuilds

Finally, ALG AK Ultimate Triggers (the AKT-ULs) Are Back In Stock

April 19, 2024 RoninsGrips

I started seeing them two weeks ago and I just ordered two. Folks, the ALG AKT-UL is hands down my favorite AK trigger. Smooth and crisp. I can’t recommend them enough. I like the Enhanced model, which is a step down, but given the choice, I’ll go for the Ultimate.

These have been out of stock literally for years – since before COVID I think, So, they are back but I have no idea how long they will be in stock so snag them while you can.

AKBuilds, Blades and Edged Weapons Including Khukuris, Firearms Building and Gunsmithing, Gunsmithing, Sten, Uzi Builds

How to do Home Manganese Parkerizing

February 13, 2024 RoninsGrips 2 Comments

The Following is a Basic Do-it-yourself Manganese Parkerizing Formula

A couple of friends online, Elkaholic and Ding, got me interested in parkerizing years ago and gave me a home brew formula and process steps they use. I have been tuning that formula for a few years and thought I would share it as I use it both for blades and firearms. It works great as either the base for a top finish, such as Molyresin or as a finish all by itself. You may be wondering “why not just buy a premade formula such as the great parkerizing solution from Brownell’s” – the short answer is because tinkering can be fun and more rewarding. I like to experiment and try different things. So, with that said, here is the recipe:

Ingredients

– 2 gallons of distilled water (it gives more consistent results because impurities have been removed – sold at supermarkets and drug stores)
– 2 “biscuits” of clean plain 0000 steel wool (thinner steel wool dissolves faster hence the use of 0000 grade)
– 1 cup of Klean Strip brand Phosphoric Prep & Etch (or other phosphoric acid etching solution around 35-45% concentrate per the Prep & Etch MSDS sheet. Dilute the acid if higher. For example, if 100% pure then go 60 water:40 acid – you can always experiment with the ratio that works for you)
– 6 rounded tablespoons of manganese dioxide (available at pottery supply stores, Amazon or eBay)

Do this outside – never in your house or shop (unless you have a great vent hood). If you do it indoors, you will likely make stuff rust fast!

As you can see, I use a camp stove. For the first couple of years I just used a Coleman stove but that was always a balancing act with my 48″ long stainless pakerizing tank that I used for barreled actions. I found the above great Camp Chef stove at Amazon and it is fantastic but any heat source will work. I like propane because its portable and not electric (to avoid any chance of electric shock) and there are tons of propane camp stoves on Amazon.

Also, be sure to use stainless steel for your tanks. I watch for sales or buy stuff off eBay. The big cooker above is from Walmart and the rectangular pan shown below is from Amazon and is normally the water pan for buffet lines.

For tongs to move stuff around, use solid stainless. I tried the plastic ones and they can leave a plastic residue on blasted surfaces and mess up your finish.

Just like baking, if you want more of the solution, take the recipe and multiply it by two, four or however many multiples you want. Just be sure you have a place to store it when done. I use 5 gallon jugs and label them.

Steps to Follow

Add acid to water in a stainless pan/pot and heat to 190F – don’t boil and waste it. I use a baking thermometer clipped to the side of the pan.
Spray each wool biscuit with brake cleaner to remove oils and allow each time to dry
As the solution warms shred the steel wool into the liquid and add the manganese dioxide
Let the mix simmer and dissolve the steel wool before adding parts
I always blast my parts before I parkerize them – I’ve heard guys tell about using a wire brush on a buffer or drill press as well but I’ve not tried that. Blasting removes the oxides and exposes the bare steel.
Make sure your parts are very, very clean and degreased — only handle with rubber gloves after they are cleaned or oils from your skin can mess things up
You can suspend your parts in the liquid with stainless wire. Leave them until the fizzing stops or about 30-40 minutes. The time varies.
Rinse the parts with boiling water thoroughly to remove the acid.
Spray parts with WD40 to get the water away from the steel
Wipe down with oil or apply whatever secondary finish you want – don’t do both 🙂 If you are going to apply a finish on top of the parkerized surface, use acetone or brake cleaner to remove any oils and then follow their instructions.

At the bottom of the post are links to Amazon products including long parkerizing tanks.

Cleaning Up

When you are done, let your mixture cool and strain the liquid through a coffee filter into a plastic can for future use. I use a blue kerosene 5 gallon container because it is a different color from all my other 5 gallon containers plus I label it. Point being, you do not want to get confused and pour this stuff in when you meant to use a fuel, etc.

The precipitate, the stuff on the bottom, should be scooped onto a shallow pan, allowed to dry and be disposed of as a hazardous waste. For example, where ever your community collects old paints, batteries, etc.

Brownells Has Great Parkerizing Solutions and Kits

Brownells sells very well regarded ready-to-use formulations. I have no hesitation at all to recommend the below items to you – they are top notch.

Click here for their manganese parkerization supplies. Their formula meets Mil Spec STD171
Click here for their zinc parkerization supplies
If you have a lot small parts you want to park, they have a bench top kit ready to go that you can buy – click here
Click here for their complete parkerizing tank system. This is a complete system for gunsmiths or others who need to park everything from small parts and pistols up to firearms and swords.

In Summary

I hope this helps you out. I’ve used the above many times and the results are solid.

Updated 2/13/24 with new sources and fixed some grammar issues.

AKBuilds

Fitting A Quick Takedown Pin To A Kalashnikov USA KP-9

July 16, 2022 RoninsGrips

August 2024 – if you haven’t heard Kalashnikov USA has declared bankruptcy and sold off all their inventory. If you are looking for 9mm AK, I’d recommend you look at the Palmetto State Armory AK-V – click here to see them.

Since Kalashinkov USA introduced the KP-9, I’ve had a handful of guys ask me to make a quick takedown pin for it. Well, it turns out it is a unique size and the hinge pin would need to be around 3.75mm – smaller than what any of my vendors could reliably hit. My existing pins all have a diameter of .156″ or about 3.96mm so they would not work.

So, what to do? I’d bought a KP-9 with their brace and it was a nice weapon in terms of fit, finish, and operation. I’d pressed out the unique hinge pin and saved it so I could have replaced it but I decided to go another route. By the way, the original pin was swollen at the ends from being set but the middle measure 3.75 so that’s the number I was going with.

There’s the hinge pin between the rear sight and the start of the dust cover rail.

There is a spring on the pin to help the dust cover pop up when the recoil rod is pushed in. Note, the fitment of the cover to the rear sight block and rear trunnion is very good. If it weren’t for the spring, the cover would stay down. By the way, the big black round thing you see on top of the barrel pin has a groove behind it. When the brace is swung into the folded position, a tab on the brace goes into the groove and holds it in the folded position.

This is the original hinge pin and the spring that pops the dust cover up. The pin is 2.75mm wide and about 24-25mm long – mine measured 24.31mm after I pressed it out. Some deformation would have occurred when it was pressed in and the ends flared open.

How To Remove The Original Pin

I used a punch on my air hammer to pop the old pin out. You could also press it out or drill it out.

I used my ATS air riveter to pop out the pin in a matter of seconds. You could press or drill out your pin.

Reaming the Hinge Hole

If you look at the hinge, there is enough material around the hinge pin material to ream it out a bit. I decided to get a 0.1563″ (3.97mm) cobalt reamer and a 4mm cobalt reamer. My thinking was to first try the smaller reamer and if that proved to be too small, I’d step up to the 4mm (0.1575″). I bought mine from McMaster-Carr but you can get them from any reputable vendor.

Reamers are cool – they make perfectly round holes and you can do them in a hand drill if you are so inclined, which I was. Secure your weapon in a vise so it can’t move, use a drill bit or other pin to align the hinge parts from the other direction. As you ream, this slave pin, or alignment pin, will be pushed out of the way as a reamer’s head is blunt.

Put your reamer in your drill chuck and coat it with cutting oil, then slowly insert the reamer into hole – let it cut – don’t force it. You’re not taking off a ton of material so I reamed the hole out in one go.

The slave pin did it’s job and I had a true hole in the end. Okay, the .1563″ reamer’s hole worked but was too tight – If you don’t intend to pull the pin much, it would work but it was not what I wanted. I then did the same thing by inserting a slave pin but this time used the 4mm reamer and it worked great.

You see, getting the hole size right matters a great deal compared to some weapons such as the M92 and Krinks – they want to cam the cover up so there is tension that locks everything in place. With the KP-9, the fit of the dustcover relative to the rear sight block is so good that there isn’t tension so you need the quick takedown pin to fit snugly and the detent ball to do its job.

Our AK-V pin fits great. This is with the 3/4″ ring installed.

Here’s the full view of the hinge. Note the detent ball on the pin that keeps it from accidentally sliding out of the hole.

The way a quick release pin that has a ball bearing detent works is that a spring is behind the ball bearing pushing it up but it is captured in the hole. By sticking up, the ball bearing limits travel. Having a circular surface if you pull hard enough during extraction then the ball bearing is pushed down, the pin pulls free and then the spring pushes the ball bearing detent back up once it is clear.. Insertion is just the reverse.

In closing

I really like how it turned out. For folks who want to add a quick takedown pin, just order the AK-V pin [click here to open that page in a new tab] and then ream your hinge open. Note, you might want to get the same size reamers and see which you prefer – start with the smaller one first of course.

The pins make removing the dust cover really easy.

AKBuilds

Super Secret AK Furniture Fitting Tool

January 26, 2022 RoninsGrips

Ok, now that I have your attention with that title, I often get asked how to fit the various furniture parts of an AK to a given rifle – the gas tube cover / upper hand guard cover, the lower handguard and the buttstock. Most of the work can be done with a secret tool – a slightly modified single cut file and patience.

For example, this is Palmetto State Armory’s Redwood furniture set on a Romy G kit I built.

Most of the time with new furniture, you need to remove material and a single cut file works great for that. With the pictured PSA Redwood furniture set, I needed to think the half circle ends of the gas tube cover and I also had to fit the lower hand guard just a tad.

This is an 8″ single cut Nicholson Handy File that I bought many years ago and modified. I prefer a single cut file so I can go slow and not remove material too fast. Just remember an old saying – *“it’s easier to take more material off than it is to put it back on.”*

Now here’s the trick to really make this tool work for fitting furniture – grind one thin side smooth – literally get rid of the file’s teeth. This will allow you to quickly and easy run the file right against a raised edge, such as the lips of the gas tube cover, and remove material that you want while leaving the raised edge untouched.

I find an 8″ file just the right size. 8″ is the measurement from the front edge, or “point” of the file, to the base of the heel – the bottom of the main body before the tang starts. The file shown is an 8″ Nicholson Handy File but any 8″ single cut or a file with single cut on one size and double-cut on another would work.

Any brand of file ought to work. Some come with a “safe” edge meaning no teeth. Just test it first to see if any of the teeth from the perpendicular surfaces protrude enough to cut – if they do then knock them down so the smooth surface can ride on the material you are working on with zero cutting happening from that side.

I used my big belt sander and removed all the teeth from this one edge and ensure it was smooth. I purposefully left the teeth on the other thin edge.

Just be patient – look at where the furniture is binding, remove a small amount and test the fit. In general, you want AK furniture to fit snug vs. rattling around. Patience is the key though – don’t rush things. Just keep inspecting, filing off a bit and testing over and over.

So everything is installed, nothing broke because I rushed and the end result is nice snug fitting furniture.

Summary

A single cut file with one thin edge ground is the secret tool but you need to be patient when using it. I can’t even begin to guess how many lower and upper handguards I have adjusted with this file over the years plus I have learned a bit more patience as well.

I hope this helps you out.

AKBuilds

How To Locate And Drill AK Front and Rear Trunnion Rivet Holes

January 2, 2022 RoninsGrips

Building an AK takes a fair amount of drilling, fitting and riveting that can intimidate someone thinking about building their first rifle. Lucky for them, the industry has evolved a lot of really cool tools exist to enable faster higher quality results. A good example of evolution is the location and drilling of the the rivet holes in the receiver for the front and rear trunnions.

Back around 2006 or so when I got started, you either measured the location of the trunnion holes and marked them or you could take a post it note, push it on the trunnion to get an outline of the holes and then transfer it to the receiver, again marking where to drill. You learned quick to start with a small drill bit so you could adjust a bit if you were off with either method – I got pretty good with the post it note method actually.

One of the AK-parts and tool vendors that has been around the longest is AK-Builder and he was always bringing new offerings to the market, I slowly added one of all of his tools as funds permitted. I had his rivet jig, flat bending jig, the top rail layout jig (if you remember those) and so forth. At some point he added a really, really cool jig for locating and drilling the holes for the trunnions. I bought it and swear by it to this day.

The jig is extremely well made and durable. When you buy it, you have options for the sizes of mandrels to fit different barrel channel holes. The red one you see works on 7.62 AKs and they also have one for 5.45 and the unique MAK90. The rounded rectangle on the right holds the rear trunnion.

Using It For The Front Trunnion Holes

Using this fixture is about as easy as it gets but you must have a drill press. I’d recommend an X-Y table on your drill if you plan to do this much but at least have a drill press.

Securely mount the fixture to your drill press.
Insert the trunnion and tighten the knob so it can’t move.
Move your drill table around to line the drill bit up with the hole in the trunnion.
Slide the receiver over the trunnion.
Lower the drill and it will go in the exact same location as the trunnion hole you lined up on.

The front trunnion is being held securely by the fixture. I am sliding the receiver forward and when I bring the drill down, it will make the hole in the exact same spot as what was in the trunnion.

This fixture is the best means I have found to quickly and accurately locate and drill the trunnion holes in the receiver. I prefer undrilled receivers because with this jig I can put the holes exactly where I want them. By the way, these are AK-Builder rivets also.

Tips For The Front Trunnion Holes

Confirm the drill bit sizes you need before you start. For most AKMs, the front rivet holes are 4mm so you can use either a 4mm or 5/32″ (3.868mm) bit. Note, that dimension can be different so just confirm is my point. Also, I’d recommend good cobalt bits personally.
Use cutting fluid – I like Tap Magic personally.
You will drill a hole at a time – do not try to go all the way through. Small alignment errors become big problems when you do that. Avoid the grief – do a hole per rivet.
Make sure the table can’t move, that the fixture is secure and that the trunnion is being held firmly. If anything moves, you are hosed.
Line up on the hole, slide the receiver all the way on, pull it back just enough to verify nothing moved one last time.
After I drill the first rivet hole I carefully inspect everything is lined up. I then move to the second rivet hole and repeat the above but before I drill, I insert temporary rivets in the holes to make sure nothing moves. DO NOT SQUISH THEM – I literally am just using their bodies to keep everything lined up. It really helps avoid small movement errors.
If you mess up real bad for some reason, weld the hole shut and start over.

If you go to the AK-Builder product page for this jig [click here] you should note the link in their description to a page with a lot of photos and detailed instructions.

Doing The Rear Trunnion

Doing the rear rivet holes uses the other side of the drilling jig. The little rectangular tab goes into the top of the rear trunnion where the recoil spring rod normally sits and you can then crank it down tight to hold it in place while drilling.

Notice the receiver will be parallel to the jig during these operations. Again, make sure everything is secure and you need to make sure the back of the receiver is true to the rear of the trunnion.

The end result will be accurately located holes. Before you set the rivets, this is when you should be thinking about a side rail for optics if you want one. I like the AKM side rail mount from AK-Builder. Those holes you will need to manually locate and drill. Use a caliper and true the top of the rail to the top of the receiver if you do install one.

Tips For the Rear

First, read all the tips I wrote for the front trunnion if you skipped them.
The key to all of this is a solid setup and nothing moving.
Confirm the size drill bit you need. It will probably be 4.5mm which you can do with that size drill or be close with 11/64″ (4.365mm).
DO NOT DRILL STRAIGHT THROUGH. I’d recommend you take your time and do a hole at a time.
Once you get a hole drilled and are ready to do the next, stick a rivet in it to prevent movement.

Summary

The AK-Builder drilling jig is the best tool I know to help you quickly and accurately locate and drill the front and rear trunnion holes in your receiver. I definitely recommend it.

AKBuilds

How To Quickly Remove AK Receiver Rivets

December 29, 2021 RoninsGrips

Okay, there are a ton of ways to remove rivets and I’ve posted some details both about removing the trigger guard and side rail rivets (if your AK has a side rail). This post is going to get straight to the point.

I use a 4.5″ cordless Ryobi angle grinder and take all the rivet heads down flush. Unless I plan to reuse the receiver, I don’t care how the receiver looks when I’m done. If I do care, then I will be much more careful and stop just before I get to the surface.

I then center punch all of the holes to make drilling easier. I like to use an automatic center punch so I can focus on where I want to make the divot for drilling vs. trying to keep everything aligned. If you’ve never used one, they are worth their weight in gold.

I drill an 1/8″ hold in each one use quality cobalt drill bits and cutting oil. I like to buy Tap Magic in bigger containers and then transfer the fluid as needed into smaller squeeze bottles with long metal tubular “needle” tips so I can precisely put it right where I need it.

From the top – 1/8″ drill bit, roll pin punch and an automatic center punch on the bottom.

I then use a roll pin punch where the rounded tip can fit in the 1/8″ hole and the shoulder properly engage the remaining rivet. Folks, this makes removing the remaining rivets super easy except for the long trunnion rivets.

For the short rivets, I like to drill them out with an 1/8″ bit to both create a hole and relieve stress. I then use a roll pin punch to easily knock them out because the ball end of the punch keeps it centered on the rivet. If you’ve ever fought with keeping a normal punch centered while hammering, a roll pin punch centered in a hole makes a night and day difference.

Long Rear Trunnion Rivets

Okay, these take more work so we’ll make a section just for these little headaches. They’re not horrible – they just take additional time to remove but I will tell you a HUGE time saver in a moment.

In general, it’s easier to remove the rivets with the trunnion out of the receiver. If you need to save the receiver, be gentle and use successively larger drill bits to remove the rivet heads so you can then pry the sheet metal receiver open and pull it out. The balancing act is that if you make the receiver holes too big then you will need to weld them shut and drill new ones. It’s not the end of the world. I prefer welding and redrilling compared to using even bigger rivets with heads that cover the holes but are mismatched to everything else.

If you don’t care about the receiver or are removing stubs, grind those heads down and use an air hammer chisel to easily bend the receiver sheet metal away from the receiver.

With the rivet heads ground off you can clearly see the rivet body outline and thus you can mark the center.

Traditional Method – drill in from each side about 1/2 way and then punch the rivet out. Guys will use 5/32″ (3.969mm) or even 11/64″ (4.366mm) drill bits. If you are spot on the center and you have access to quality cobalt metric bits, this is usually a 4.5mm rivet so you could use that. You will read about guys suggesting 3/16″ drills but this route is problematic because 3/16″ is 4.762mm and thus too large. You’d need to use a 3/16″ rivet to properly secure the trunnion and the heads will look noticeably different from the others.

Old school – drill the rivet out most of the way and then punch it out the rest. You can see the pin exiting to the left. Note, do this on a hard surface that isn’t going to flex and absorb some of your blows. Here I am literally beating the crap out of the punch on the concrete floor. I’ve since moved on to a method using an air hammer that I will describe next.

The impatient Ronin method – drill 1/8″ centered holes in one side of the rivets left in the trunnion. Make or buy an 1/8″ air hammer drift pin and chase each long rivet out in a matter of seconds. It’s amazingly fast. I don’t know who invented the air hammer but it is seriously magical when it comes to tasks like this.

I can pop out a rivet in seconds using an air hammer and my rivet fixture. I took two old .401 shank air tools and drilled center holes. One is 1/8″ and the other is 5/32″. I then have a variety of lengths of 1/8″ and 5/32 dowel pins to do the job. I built both diameters but really I just use the 1/8″ punch now. I put the trunnion in a heavy metal working vise and start with a short pin to start the push and then a longer pin to chase it all of the way out. It works like a dream. If you do this, please, please, please wear safety glasses. A hardened dowel pin can brake in these situations. For an air hammer, I am using an IR 116 – a 4x air riveter ought to work also, I have a 3x ATS but have never tried it for this.

Summary

Use an angle grinder to knock off the rivet heads, drill and punch out the short rivets. For the longer rivet, decide which of the two methods you want to use. I hope this helps you out!

Section 1: Introduction – Deconstructing the Myth of Soviet “Cosmoline”

Section 2: A Comparative Analysis: Soviet ПВК vs. American Cosmoline

The Soviet Standard: ГОСТ 19537-83 and Смазка ПВК

The American Counterpart: MIL-C-11796C and Cosmoline

Table 1: Comparative Properties of Soviet ПВК vs. American Cosmoline

Section 3: The Doctrine of Preservation: Why the Red Army Greased Everything

Strategic Depth and Long-Term Storage

Warfare in a Harsh Climate

A System, Not a Substance: The ЕСЗКС

Section 4: The Aging Process: From Viscous Grease to Hardened Shell

Mechanisms of Aging: Evaporation and Oxidation

Intended Lifespan and the Reality of Strategic Reserves

The Challenge of Hardened Preservative: Then vs. Now

Section 5: The Official Soviet Method: Расконсервация per GOST 9.014-78

Reconstructing the Official Protocol

The Doctrine of “Good Enough” in Practice

Section 6: The Modern Armorer’s Guide: Top 5 Removal Methods Evaluated

General Principles for All Methods

Method 1: Heated Ultrasonic Cleaning

Method 2: Solvent Immersion

Method 3: Thermal Application (Non-Immersion)

Method 4: Aqueous Immersion (Boiling Water)

Method 5: Manual Cleaning with Modern Degreasers

Table 2: Ranking of Modern Removal Methods

Section 7: Conclusion and Recommendations

Glossary of Key Russian Terms

Works cited

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Parts you will need

Removing the old stock

Adding the new stock

If you want to insert a mercury recoil reducer

Let’s continue with installing the buffer tube

End Result

Summary

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Ingredients

Steps to Follow

Cleaning Up

Brownells Has Great Parkerizing Solutions and Kits

In Summary

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How To Remove The Original Pin

Reaming the Hinge Hole

In closing

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Summary

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Using It For The Front Trunnion Holes

Tips For The Front Trunnion Holes

Doing The Rear Trunnion

Tips For the Rear

Summary

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Long Rear Trunnion Rivets

Summary

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When Strength and Quality Matter Most