Gunsmith Part: Troubleshooting Common AR-15 Misfires and Failures to Feed

The Bolt Carrier Group’s Role

Examining the Firing Pin

At the heart of the AR-15’s operation lies the bolt carrier group (BCG). This assembly is a complex system responsible for cycling the action, extracting spent casings, and chambering new rounds. Any malfunction within the BCG can lead to a failure to feed, a failure to extract, or, in some cases, a complete stoppage.

One of the most frequent culprits behind misfires and failures to feed is a faulty firing pin. The firing pin is a crucial element for igniting the primer and enabling the cartridge to discharge. A worn, damaged, or improperly installed firing pin can result in weak strikes or, worse, no strike at all. Examining the firing pin is therefore a prime directive when encountering misfires.

Begin by field stripping the BCG and removing the firing pin. Carefully inspect the firing pin for any signs of damage, such as bending, chipping, or wear. If the firing pin has sustained damage, it must be replaced. If damage isn’t immediately visible, clean the firing pin channel and the firing pin itself. Lubrication plays an essential role in the proper function of the firing pin. A dry firing pin channel can hinder the pin’s movement, leading to a light strike. Use a quality firearm lubricant to ensure smooth operation.

Inspecting the Bolt

Another crucial component within the BCG is the bolt itself. The bolt head houses the extractor, a small but essential claw that grips the cartridge rim to extract the spent casing. An extractor that’s chipped, worn, or damaged can fail to extract the spent casing, leading to a failure to feed the next round. The extractor also plays a role in preventing double feeds, as an extracter that is working correctly will take the casing out of the way of the next bullet.

Examine the extractor claw closely. Make sure there is no debris hindering the action of the extractor claw, especially in the extractor spring and o-ring. Consider replacing the extractor spring, or even the whole extractor assembly. Extractor springs and o-rings tend to wear out from use.

Examining the Magazine and its Importance

While the BCG is the workhorse of the AR-15’s operational cycle, the magazine is the ammunition’s holding chamber, and can be the cause of many malfunctions. Issues with magazines are a frequent source of feeding problems, making it vital to verify their functionality first.

Checking the Magazine Spring

A common issue is a damaged or malfunctioning magazine spring. The spring provides the force needed to push the rounds up into the chamber. A weakened or broken spring can fail to feed rounds correctly.

Disassemble the magazine and inspect the spring. The spring should have sufficient tension and extend to its proper length. Replace the magazine spring if necessary. Consider investing in high-quality magazines from reputable manufacturers, such as Magpul or Lancer. These magazines are known for their durability and reliability.

Inspecting the Feed Lips

The feed lips of the magazine play a crucial role in guiding rounds into the chamber. Over time, the feed lips can be bent or damaged, causing improper feeding. Inspect the feed lips carefully for any signs of damage. Use a specialized magazine feed lip tool, or, failing that, the correct size of needle-nose pliers to carefully adjust the feed lips if necessary. Be extremely cautious when making adjustments, as over-bending the feed lips can damage the magazine.

Checking the Follower

Additionally, the magazine follower can be a cause. The follower pushes the ammunition upwards for each successive firing. If the follower is broken, it can cause failure to feed issues. Inspect the follower, and replace it as needed.

Checking Gas System Functionality

The AR-15’s gas system is the engine that drives the entire operational cycle. It channels high-pressure gas from the fired round to operate the bolt carrier group. Any problem in the gas system, whether it’s a leak, a blockage, or improper alignment, can cause malfunctions like short stroking, a failure to extract, or a failure to feed.

Inspecting the Gas Tube

Begin by inspecting the gas tube. The gas tube is a slender, metal tube that runs from the gas block to the upper receiver and into the carrier group. A damaged or blocked gas tube will prevent the gas from reaching the carrier group and, subsequently, will make the whole system malfunction. Remove the gas tube to inspect it for any obstructions, such as carbon buildup, rust, or debris. Use a pipe cleaner or a specialized gas tube cleaning tool to remove any blockages.

Checking Gas Block Alignment

Examine the gas block for proper alignment with the gas port on the barrel. The gas block must be securely fastened to the barrel, and the gas port must be clear and aligned with the gas tube. A misaligned or improperly sealed gas block can result in a gas leak, which may also cause misfires.

Checking Gas Rings

Next, check the gas rings on the bolt carrier. The gas rings create a seal between the bolt and the chamber to ensure proper gas pressure. Worn or damaged gas rings can lead to gas leaks, again affecting the proper function of the system. Replace gas rings as needed.

Exploring Ammunition and Chamber Issues

The ammunition itself is a critical factor in determining the reliability of any firearm. Using low-quality or improperly sized ammunition can lead to a host of problems, including misfires and failures to feed.

Issues with Failure to Chamber

One of the most common ammunition-related issues is a failure to chamber. This often stems from a round that doesn’t properly fit the chamber, either due to an oversized bullet or a slightly out-of-spec case. To rule out ammunition as a potential cause, try using ammunition from a known, reputable manufacturer. If the problem disappears, the ammunition was the likely culprit.

Maintaining a Clean Chamber

Ensure the chamber is free of obstructions, debris, or excessive carbon buildup. A dirty chamber can lead to extraction problems and, ultimately, failures to feed. Thoroughly clean the chamber using a chamber brush and solvent.

Inspect the Cartridge Rim

The rim of the casing also plays a role in the firing of ammunition. The extractor, as mentioned before, grips the casing, and the cartridge rim is vital in this process. Inspect the rim of the casing for any damage.

Troubleshooting Trigger and Hammer Problems

Although less common than other causes, malfunctions in the trigger and hammer assembly can contribute to misfires. A trigger that doesn’t properly release the hammer, or a hammer that doesn’t deliver enough force to the firing pin, can prevent the cartridge from igniting.

Inspect the trigger and hammer for any signs of damage, such as wear, bending, or broken parts. Ensure the hammer engages properly with the sear. Check the trigger pull weight to ensure it’s within the recommended specifications. If the trigger pull is excessively heavy, it can affect accuracy and, potentially, cause light strikes. If you have any doubts, consult a professional gunsmith to assess these components, especially if you are unsure of the inner workings.

Practical Field Stripping and Lubrication Strategies

Proper maintenance is crucial in preventing malfunctions. A well-lubricated AR-15 is less prone to failures.

Begin by field stripping the rifle, as described earlier, to examine the essential components. Clean all metal parts with a quality firearm cleaner. Remove all old lubricants and debris. Reassemble the rifle, and apply a thin coat of firearm lubricant to all moving parts, including the bolt carrier group, the charging handle, and the trigger assembly.

Apply lubricant judiciously, avoiding excess. Too much lubricant can attract dirt and debris, causing malfunctions. Use a high-quality lubricant designed specifically for firearms.

Expert Advice for the Aspiring Gunsmith

“When troubleshooting AR-15 malfunctions, approach the problem methodically,” advises John Smith, a certified gunsmith with over 20 years of experience. “Start with the simplest checks first – the magazine, ammunition, and lubrication – and then gradually work your way toward the more complex components. Patience, attention to detail, and a good understanding of how the rifle functions are key to successful troubleshooting. Do not be afraid to consult a qualified gunsmith if you’re unsure of any step of the process.” Remember, a systematic approach will save time and prevent unnecessary repairs.

Summary of Key Insights

We’ve covered the critical aspects of troubleshooting misfires and failures to feed in your AR-15. From the bolt carrier group and magazine to the gas system, ammunition, and trigger assembly, understanding these components is key to resolving malfunctions. Regular maintenance, proper lubrication, and a methodical approach to troubleshooting are vital for ensuring your AR-15’s reliability. By following these steps, you can increase your enjoyment, and minimize downtime caused by malfunctions. Remember, the pursuit of gunsmith part expertise is a journey, not a destination.

Now that you have a solid understanding of the major causes of these problems, you can confidently begin diagnosing and resolving them.

Looking Ahead

In our next installment, we’ll delve into [a different topic of gunsmithing, perhaps cleaning or upgrading the handguard]

Final Thoughts

Mastering the skills to diagnose and fix AR-15 malfunctions is essential for any firearm enthusiast. With patience, practice, and a thorough understanding of the rifle’s mechanics, you can keep your AR-15 running smoothly and reliably, ensuring its readiness when you need it most. Always prioritize safety and consult with a qualified gunsmith if needed.