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AR-15/M4 Firearm Maintenance: Part 3 Lubrication

In the ongoing series of ‘AR-15/M4 Firearm Maintenance,’ we will now turn our focus towards a vital part of sustaining your firearm – lubrication. Ensuring correct lubrication is as imperative for the proper functioning of your rifle as avoiding over lubrication, which could be equally harmful.

During this process, care must be taken to sparingly oil the carrier exterior, concentrating on the four bearing surfaces that come into contact with the receiver. This precious step aids in friction reduction, culminating in a smoothly running device. The trigger is another component deserving attention, a needle oiler being your tool of choice for this. A word of caution, though: excessive lubrication should be averted for reliable weapon cycling. Following a thorough clean and lubrication procedure, the next step encompasses final reassembly.

Discover more about the AR-15/M4 Firearm Maintenance: Part 3 Lubrication.

Table of Contents

Understanding the Importance of Lubrication

Every piece of mechanical equipment requires maintenance to ensure a long lifespan and efficient operation. This is particularly true for firearms like the AR-15/M4. Let’s delve into the importance of lubrication for these firearms.

Why lubrication is crucial for AR-15/M4

Lubrication plays an indispensable role in the upkeep of your AR-15/M4. It keeps the weapon functioning smoothly, providing the necessary slipperiness between the firearm’s moving parts to decrease friction. This in turn reduces wear and tear, prevents overheating, and extends the gun’s operational life.

Implications of improper lubrication

Improper lubrication – be it too much or too little, can detrimentally impact your firearm’s performance. Incorrect lubrication can lead to carbon build-up, overheating, and accelerated wear rates. Over time, it can also lead to functional failures such as jams, misfires, or even catastrophic malfunctions that could potentially be unsafe.

Effects of over-lubrication and under-lubrication

Both over-lubrication and under-lubrication carry their own set of problems. Over-lubrication can cause excess dirt and dust to adhere to the firearm, leading to mechanical issues. Conversely, under-lubrication might increase friction, causing parts to wear out or potentially fail prematurely.

Choosing the Right Lubricant

Having understood the importance of lubrication, your next step is selecting the right lubricant for your AR-15/M4.

Types of firearm lubricants

Firearm lubricants come in various forms, including oil, grease, and in some cases, dry film lubricants. Each type has its pros and cons, depending on the environmental conditions and how the firearm is used.

How to determine the best lubricant for AR-15/M4

Several factors influence the right lubricant choice. These can include the climate and environment in which your AR-15/M4 is used, the frequency of use, and your personal preference. Researching and testing a variety of products will help you arrive at the ideal choice.

Careful consideration of lubricant brands

With numerous brands on the market, careful consideration is vital. Some brands might suit your specific circumstances better than others. Reading product reviews, user experiences, and firearm-related forums can provide valuable insights to aid in your decision.

Preparing for Lubrication

Preparation plays a crucial role in ensuring a thorough lubrication process.

Assembling necessary equipment

Before you start, assemble all required tools and materials. This typically includes the lubricant, cleaning supplies, and specific instruments necessary for accessing different parts of the firearm.

Safety precautions prior to lubrication

Safety should always be your primary concern. Prior to the lubrication process, ensure your firearm is unloaded to prevent accidental discharge. Always follow firearm safety rules throughout the process.

Cleaning the firearm before lubrication

Prior to lubrication, your firearm should be thoroughly cleaned. This prevents the mixing of lubricant with dirt or debris, which could hinder the firearm’s functionality.

AR-15/M4 Firearm Maintenance: Part 3 Lubrication

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Outer Carrier Lubrication

Outer carrier lubrication is an essential part of the maintenance process.

Understanding the four bearing surfaces

The outer carrier of your AR-15/M4 contains four bearing surfaces where it contacts the receiver. These surfaces are crucial as they are subject to the most friction during operation.

How to apply lubricant on the exterior of the carrier

The purpose of lubricating these surfaces is to reduce friction. To do this, lightly oil the exterior of the carrier, focusing particularly on the four bearing surfaces.

Managing friction through outer carrier lubrication

This careful application helps manage friction effectively, allowing your firearm to work smoothly and prolonging its life.

Trigger Lubrication

Trigger lubrication is a critical, yet often overlooked, part of AR-15/M4 maintenance.

Tools needed for trigger lubrication

Using a needle oiler can facilitate the process. This handy tool allows you to avoid over-lubrication while ensuring you’re still delivering sufficient lubrication to necessary areas.

Steps to lubricating the trigger and hammer pins

Just a few drops on the trigger and hammer pins are enough. An oiler ensures that these drops are delivered accurately, maximizing the effect while minimizing waste.

Tips on grease application to bearing surfaces

In some cases, light greasing of the bearing surfaces of the sear and disconnector is recommended, particularly for some aftermarket triggers. However, with a standard fire control group, this is typically unnecessary.

Aftermarket Triggers: Special Lubrication Guidelines

There are particular lubrication guidelines to consider when you have aftermarket triggers.

Situations when grease on sear and disconnector is necessary

Some aftermarket trigger manufacturers suggest lightly greasing the bearing surfaces of the sear and disconnector. If that is the case with your aftermarket trigger, it’s crucial to follow the guidelines set forth by the manufacturer.

Guidance from manufacturers on aftermarket trigger lubrication

Manufacturer instructions should always be followed closely to maintain the trigger’s high performance and longevity.

Differences between standard and aftermarket trigger lubrication

Understanding the differences between lubricating standard and aftermarket triggers is key. Non-compliance with these differences can lead to inadequate lubrication and potential mechanical issues.

Avoiding Over Lubrication

While ensuring your AR-15/M4 is well-lubricated is vitally important, it is also imperative to avoid the pitfalls of over-lubrication.

Why over lubrication hinders firearm function

Over-lubrication can be detrimental due to the accumulation of excess dirt and grime. It can also pave the way for over-reliance on lubrication, which fails to address underlying issues such as wear and tear.

Strategies to avoid over lubricating your AR-15/M4

Utilizing a needle oiler and closely following manufacturers’ guidance can help prevent over-lubrication. Additionally, regular cleaning can aid in avoiding an excess buildup of lubricant.

Detecting signs of over-lubrication

Indications of over-lubrication can include a sluggish performance, frequent jamming, and excessive grime buildup. If you observe these signs, consider revising your lubrication protocol.

Post Lubrication Steps

Upon completion of the lubrication process come necessary post-lubrication steps.

Properly storing lubricated firearm

Proper storage is integral to keeping your firearm in optimal condition. This includes storing your firearm in a dry, cool location, ideally within a gun safe.

Frequency of lubrication – when do you need to do it next

The frequency of lubrication varies depending on usage and environmental conditions. As a general rule, your firearm should be cleaned and lubricated after each use.

Subsequent care steps after lubrication

Beyond lubrication, regular inspection and cleaning should be incorporated into your maintenance routine to keep your firearm functioning at its best.

Reassembly after Lubrication

Following lubrication, it’s time to focus on reassembling your firearm.

Preparing for reassembly

Ensure all parts are properly lubricated and cleaned before reassembling. Lay out all of the components in an organized fashion to simplify the process.

Step by step guide to reassembling a lubricated AR-15/M4

Gradually reassemble your firearm, ensuring each part is correctly oriented and firmly secured. Patience is key during this process as rushing can potentially lead to mistakes.

Tips for successful reassembly after lubrication

Familiarize yourself with your firearm’s individual components and their specific assembly sequence. If you’re unsure, referencing a guide or instructional video can be invaluable.


In conclusion, irrespective of the firearm type, proper lubrication is crucial. It keeps your firearm functioning smoothly, prolongs its lifecycle, and mitigates common mechanical problems.

Recap of the importance of proper lubrication

The importance of proper lubrication cannot be overstated. It is a transformative form of preventative care, saving potential costs and issues down the line.

Reminders about good lubrication habits

It’s crucial to remember that successful lubrication depends on both the correct choice of lubricant and application techniques. Regular maintenance and avoidance of over-lubrication are crucial habits to adopt.

Continuing maintenance beyond lubrication

Remember that while lubrication forms an integral part of firearm maintenance, your responsibility doesn’t end there. Regular cleaning, inspection, and correct storage are essential steps to ensure your firearm remains in optimum condition.

By understanding these steps, you are well on your way to maintaining your AR-15/M4 effectively and ensuring many years of reliable service.

Check out the AR-15/M4 Firearm Maintenance: Part 3 Lubrication here.