Examples of AR-15 Bolt Failures

Published on December 5, 2020
Duration: 3:42

This video details common AR-15 bolt failures, including cracks at the cam pin hole and broken lugs. It highlights how nickel boron and nitrided bolts can fail catastrophically, and that military-spec Carpenter 158 bolts from M16s/M4s are also susceptible to lug breakage. Proper inspection during cleaning, focusing on the cam pin hole and lug sides, is crucial. A warped bolt from a crack can cause firing pin binding, leading to 'click no bang' malfunctions.

Quick Summary

AR-15 bolts commonly fail due to cracks at the cam pin hole or broken locking lugs. Inspect your bolt during cleaning, focusing on these areas. Difficulty seating the firing pin is a key sign of a cracked bolt causing warping and potential malfunctions.

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 common failure points for AR-15 bolts?

Common failure points for AR-15 bolts include cracks originating from the cam pin hole and breakage of the locking lugs, especially near the extractor. Both coated and uncoated bolts can experience these issues.

How can I inspect my AR-15 bolt for damage?

During cleaning, thoroughly inspect the bolt for cracks around the cam pin hole and check the locking lugs for any signs of fracturing or wear. Pay close attention to both sides of the lugs.

What does it mean if my firing pin is hard to seat in an AR-15?

Difficulty seating the firing pin often indicates a cracked bolt. The crack can cause the bolt body to warp slightly, creating friction that impedes the firing pin's movement, leading to misfires.

Are certain AR-15 bolt materials more prone to failure?

While coatings like Nickel Boron and Nitride can fail, even military-spec Carpenter 158 steel bolts used in M16s and M4s are susceptible to lug failures. Regular inspection is key regardless of material.

Related News

All News →

More Gunsmithing & DIY Videos You Might Like

More from School of the American Rifle

View all →