Understanding AR-15 Failure to Lock Back: A Comprehensive Guide

When it comes to the AR-15, one of the most common issues that shooters encounter is the failure to lock back. This problem can be frustrating, especially during critical moments. In this article, we will delve into the various aspects of AR-15 failure to lock back, including its causes, symptoms, and potential solutions. By the end of this guide, you should have a clearer understanding of this issue and how to address it effectively.

What is Failure to Lock Back?

Failure to lock back refers to a situation where the bolt on an AR-15 rifle does not fully lock into the rear position after the last round is fired. This can happen due to various reasons, and it is important to identify the cause before attempting any fixes.

Causes of Failure to Lock Back

There are several factors that can contribute to the failure to lock back on an AR-15 rifle:

• Dirty or worn bolt carrier group (BCG): Over time, the BCG can accumulate dirt and debris, leading to a failure to lock back. Regular cleaning and maintenance are essential to prevent this issue.

• Improperly fitted parts: If the parts of the rifle are not properly fitted, it can cause the bolt to fail to lock back. This includes the bolt, bolt carrier, and extractor.

• Worn extractor: A worn extractor can prevent the bolt from locking back properly. This is because the extractor is responsible for holding the cartridge case in place during the ejection process.

• Improperly adjusted extractor spring: If the extractor spring is not adjusted correctly, it can cause the bolt to fail to lock back. This is because the spring is responsible for applying pressure to the extractor, which in turn holds the cartridge case in place.

• Debris in the chamber: Sometimes, debris can accumulate in the chamber, preventing the bolt from locking back. This can happen if the rifle is not cleaned properly or if it is used in sandy or dusty environments.

Symptoms of Failure to Lock Back

There are several symptoms that can indicate a failure to lock back on an AR-15 rifle:

• The bolt does not fully lock into the rear position after the last round is fired.

• The bolt carrier group moves forward with the bolt, indicating that it is not fully locked back.

• The rifle fails to cycle properly after the last round is fired.

Diagnosing the Issue

Diagnosing the cause of a failure to lock back on an AR-15 rifle requires a careful inspection of the rifle. Here are some steps you can follow:

• Check the BCG for signs of wear or damage.

• Inspect the bolt, bolt carrier, and extractor for proper fit and function.

• Ensure that the extractor spring is adjusted correctly.

• Check the chamber for debris.

Fixing the Issue

Once you have identified the cause of the failure to lock back, you can take steps to fix the issue. Here are some potential solutions:

• Clean the BCG thoroughly, including the bolt, bolt carrier, and extractor.

• Replace worn or damaged parts, such as the extractor or extractor spring.

• Ensure that all parts are properly fitted and adjusted.

• Check the chamber for debris and clean it if necessary.

Preventing Future Issues

Preventing future failures to lock back on an AR-15 rifle involves regular maintenance and proper care. Here are some tips to help you keep your rifle in good working order:

• Clean your rifle regularly, especially after use in dusty or sandy environments.

• Inspect your rifle regularly for signs of wear or damage.

• Keep your rifle stored in a cool, dry place when not in use.

• Use quality ammunition and follow the manufacturer’s recommendations for maintenance and care.