The AR-15 platform, while generally reliable, can sometimes experience malfunctions. One common issue is a failure to feed the second round, where the rifle cycles the first round successfully but jams on the second. This problem can stem from various causes, ranging from simple fixes like magazine issues to more complex mechanical problems. This comprehensive guide will delve into the common causes, troubleshooting steps, and solutions for this frustrating malfunction.
Understanding the AR-15 Feeding Mechanism
Before diving into troubleshooting, let's briefly review the AR-15's feeding process. The bolt carrier group (BCG) cycles rearward, extracting and ejecting the spent casing. As the BCG moves forward, the bolt strips a round from the magazine and chambers it. A failure to feed the second round usually indicates a disruption in this precise sequence.
Key Components Involved in Feeding:
- Magazine: The magazine's design, spring tension, and follower all play a crucial role. A weak spring, damaged follower, or improperly seated magazine can cause feeding problems.
- Bolt Carrier Group (BCG): The BCG's proper functioning is paramount. Issues like gas system malfunctions or BCG wear can affect feeding reliability.
- Bolt: The bolt's ability to reliably strip rounds from the magazine is crucial. A damaged or improperly lubricated bolt can contribute to feeding issues.
- Upper Receiver: Alignment and proper functioning of the upper receiver components influence feeding. A damaged upper receiver can lead to malfunctions.
Common Causes of AR-15 Failure to Feed Second Round
Several factors can contribute to an AR-15's failure to feed the second round. Let's break down the most frequent culprits:
1. Magazine Issues:
- Weak Magazine Spring: A weakened magazine spring can fail to push rounds up reliably, especially towards the end of the magazine's capacity. This is a very common cause of failures to feed, particularly on the second round after the initial round has been fed.
- Damaged or Dirty Magazine Follower: A bent or damaged follower can interfere with the smooth upward movement of rounds, preventing the bolt from stripping the next cartridge. Dirt and debris can also impede follower movement.
- Improperly Loaded Magazine: Rounds loaded at an angle or improperly stacked can lead to feeding problems. Always ensure rounds are seated correctly and vertically in the magazine.
- Magazine Compatibility: Not all magazines are created equal. Using low-quality or incompatible magazines can result in feeding issues. Stick to reputable brands known for their reliability.
2. Ammunition Problems:
- Type of Ammunition: Certain ammunition types, such as those with overly lubricated cases or unusually shaped bullets, can lead to feeding difficulties.
- Damaged Ammunition: Damaged or dented cartridge cases can cause malfunctions. Always inspect your ammunition before use.
3. Bolt Carrier Group (BCG) Problems:
- Gas System Issues: If your gas system is over-gassed or under-gassed, it can affect the BCG's cycling speed and timing, leading to feeding problems. This can manifest as a failure to feed the second round.
- BCG Wear: Excessive wear on the BCG components, including the bolt, cam pin, and carrier, can lead to malfunctions.
4. Upper Receiver Issues:
- Misalignment: Improper alignment of the upper and lower receivers can lead to feeding problems. Make sure everything is properly aligned and tight.
- Damage: Damage to the upper receiver, such as dents or cracks, can interfere with the smooth operation of the components.
Troubleshooting and Solutions
Troubleshooting an AR-15 failure to feed the second round requires a systematic approach. Here's a step-by-step guide:
- Inspect the Magazine: Start by inspecting the magazine for any damage, dirt, or wear to the follower or spring. Replace the magazine with a known good one. Try several magazines if possible.
- Check the Ammunition: Examine your ammunition for any damage or unusual characteristics. Try different ammunition if available.
- Clean the Rifle: Thoroughly clean your rifle, paying special attention to the bolt carrier group, chamber, and magazine well. Dirt and debris can interfere with feeding.
- Lubricate the Rifle: Proper lubrication is crucial. Use a high-quality gun oil and lubricate moving parts, including the BCG, bolt, and receiver rails.
- Inspect the BCG: Check the BCG for signs of wear or damage. If you notice any issues, replace the BCG.
- Check the Gas System: If you suspect gas system issues, have a gunsmith evaluate your gas system for proper tuning.
- Verify Upper and Lower Receiver Alignment: Ensure the upper and lower receivers are correctly aligned and tightened.
Case Study: The "Weak Spring" Scenario
A common scenario involves a shooter consistently experiencing failure to feed the second round after firing several rounds from a magazine. After thorough inspection, the problem was traced to a magazine with a significantly weakened spring. The weakened spring lacked the necessary force to push rounds up consistently, leading to this specific malfunction. Replacing the magazine with a new one completely resolved the issue.
Conclusion: Preventing AR-15 Feeding Problems
While failures to feed the second round can be frustrating, they are often preventable. Regular cleaning, lubrication, and using high-quality magazines and ammunition are critical. By understanding the feeding mechanism and systematically troubleshooting potential issues, you can ensure your AR-15 functions reliably. Remember that seeking the assistance of a qualified gunsmith for more complex problems is always a safe and effective course of action.