Examples of AR-15 Bolt Failures

Published on December 5, 2020
Duration: 3:42

This guide, presented by School of the American Rifle, details common AR-15 bolt failures, including cracks at the cam pin hole and broken locking lugs. It emphasizes thorough inspection during cleaning to identify potential issues like warping that can cause firing pin binding, leading to 'click no bang' malfunctions. Proper maintenance can prevent catastrophic failures in the field.

Quick Summary

Common AR-15 bolt failures include cracks originating from the cam pin hole and broken locking lugs. Thorough inspection during cleaning is vital; look for hairline fractures and damage to lugs. Difficulty seating the firing pin suggests bolt warping, a precursor to 'click no bang' failures.

Chapters

  1. 00:00Nickel Boron Bolt Cracks
  2. 00:40Catastrophic Bolt Failures
  3. 01:10Bolt Lug Failures
  4. 02:00Maintenance and Inspection Tips
  5. 02:40Identifying Cracks via Firing Pin

Frequently Asked Questions

What are the most common failure points for an AR-15 bolt?

The most common failure points for an AR-15 bolt are the cam pin hole and the locking lugs. Cracks often initiate at the cam pin hole, and lugs can break, especially around the extractor area. Warping due to internal fractures can also cause firing pin issues.

How can I identify a failing AR-15 bolt?

Inspect the bolt thoroughly during cleaning. Look for hairline cracks around the cam pin hole and any signs of damage or missing material on the locking lugs. Difficulty seating the firing pin is also a key indicator of internal bolt warping.

Are Nickel Boron or Nitride bolts more prone to failure?

Both Nickel Boron and Nitride coatings can be found on bolts that fail. Failures typically occur at the same stress points, like the cam pin hole. The underlying bolt material and manufacturing quality are more critical than the coating itself.

What is the significance of Carpenter 158 steel in AR-15 bolts?

Carpenter 158 is a high-strength steel alloy commonly used in military-spec M16 and M4 bolts. While strong, it is known to be susceptible to fatigue and fracture at specific stress points, necessitating careful inspection.

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