Quick Tip: Fixing Common AR-15 Gas System Problems

Published on March 3, 2021
Duration: 5:19

This video provides a practical guide to diagnosing and fixing common AR-15 gas system issues. It details how to identify over-gassing by ejection patterns and suggests solutions like adjustable gas blocks. The content also covers under-gassing causes, such as loose gas blocks or tubes, and emphasizes inspecting the bolt carrier group's gas key and gas rings for wear or leaks. Proper gas tube alignment is highlighted as a critical, often overlooked, factor.

Quick Summary

Identify AR-15 gas system problems by ejection pattern: forward ejection indicates over-gassing. Check for leaks at the gas block, gas tube, and the bolt carrier group's gas key. Test gas rings by standing the BCG on its bolt; it shouldn't collapse.

Chapters

  1. 00:00Introduction to AR-15 Gas System Issues
  2. 00:20Identifying and Fixing Over-Gassing
  3. 01:05Diagnosing Under-Gassing and Leaks
  4. 01:50Inspecting the BCG Gas Key
  5. 02:10Testing for Worn Gas Rings
  6. 04:15Checking Gas Tube Alignment

Frequently Asked Questions

How can I tell if my AR-15 is over-gassed?

Observe your AR-15's brass ejection pattern. Normal ejection is typically between 3 and 5 o'clock. If the brass is consistently ejected forward of the 3 o'clock position, your rifle is likely over-gassed, indicating too much gas is entering the system.

What causes an AR-15 to under-gas and short cycle?

Under-gassing often stems from leaks or insufficient gas. Check for loose fits between the gas block and barrel, or the gas tube and gas block. Also, inspect the bolt carrier group's gas key for proper staking and tightness, as leaks here are a common culprit.

How do I test the gas rings on my AR-15 bolt carrier group?

A simple test for worn gas rings involves standing the bolt carrier group upright on its bolt. If the BCG collapses under its own weight, the gas rings are worn and need replacement to ensure proper sealing and gas function.

What is the significance of gas tube alignment in an AR-15?

Proper gas tube alignment is crucial. If the tube is misaligned, it can rub against the carrier key, causing erosion over time. This wear can lead to gas leaks, contributing to under-gassing issues and potentially damaging components.

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