AO Precision BCG Physical

Published on February 20, 2020
Duration: 20:06

This video provides a detailed physical inspection and reassembly guide for an AO Precision Bolt Carrier Group (BCG). The instructor, from School of the American Rifle, highlights common issues like a protruding ejector roll pin and undersized extractor pockets, demonstrating how to correct them. The guide covers disassembly, component inspection, spring replacement, and reassembly, emphasizing proper tool usage and attention to detail for a functional BCG.

Quick Summary

The AO Precision Bolt Carrier Group inspection revealed a protruding ejector roll pin and an undersized extractor pocket, common issues requiring careful correction. The internal finish also showed machining lines. The instructor recommends replacing springs with known quality options and ensuring the ejector roll pin is properly recessed to prevent cycling malfunctions.

Chapters

  1. 00:00Introduction to AO Precision BCG Physical
  2. 00:40Disassembly: Firing Pin and Cam Pin
  3. 01:08Bolt and Gas Rings Inspection
  4. 01:20Extractor Removal and Inspection
  5. 02:00Ejector and Roll Pin Issue
  6. 03:07Using Bolt Vise for Ejector Removal
  7. 04:39Dealing with Stubborn Roll Pins
  8. 06:09Ejector Removal and Spring Replacement
  9. 07:38Installing New Ejector Roll Pin
  10. 09:27Installing New Extractor
  11. 10:13Oversizing Extractor Pocket with Dremel
  12. 11:56Headspace Check
  13. 12:22Magnetism Check
  14. 13:04Firing Pin Protrusion Check
  15. 13:44Cam Pin Fit and Replacement
  16. 14:09Firing Pin Hole and Bolt Tail Check
  17. 14:23Carrier Inspection: Gas Key and Length
  18. 15:31Carrier Bore Dimensions
  19. 16:36Internal Carrier Finish
  20. 17:16Gas Key Staking Test
  21. 18:05Reassembly with SOTAR Cam Pin
  22. 18:46Final BCG Inspection and Summary

Frequently Asked Questions

What common issues were found on the AO Precision Bolt Carrier Group?

The AO Precision BCG had a protruding ejector roll pin that could cause jamming and an undersized extractor pocket that prevented proper seating. The internal finish of the carrier also showed machining lines, potentially leading to accelerated gas ring wear.

How can an undersized extractor pocket be fixed?

An undersized extractor pocket can be carefully enlarged using a Dremel tool with a diamond bit. The goal is to slightly widen the pocket to allow the extractor to seat correctly without drilling deeper.

Why is it important for the ejector roll pin to be recessed?

The ejector roll pin must be recessed to prevent it from catching on the barrel extension during cycling. A protruding pin can cause malfunctions and damage to both the BCG and the firearm.

What are recommended replacements for BCG springs?

The instructor recommends replacing springs from unknown sources with known quality options like chrome silicon ejector springs or Colt Gold extractor springs, as spring quality is crucial for BCG reliability.

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