Anderson BCG Physical

Published on July 5, 2020
Duration: 23:35

This video provides a detailed physical inspection and diagnostic analysis of an Anderson Manufacturing bolt carrier group. The instructor meticulously examines various components, including the carrier's exterior finish, gas rings, bolt wear, firing pin protrusion, extractor, and cam pin. It highlights potential failure points such as sharp edges on the carrier, short firing pin protrusion, magnetism in components, and wear on the bolt lugs and tail, offering insights into diagnosing and understanding BCG issues.

Quick Summary

An expert inspection of an Anderson Manufacturing bolt carrier group revealed several potential issues including sharp exterior edges, short firing pin protrusion (.026"), erratic bolt wear, weak ejector spring, and a bolt tail that failed a no-go gauge test, indicating potential gas leakage. Magnetism in components and loose gas key screws were also noted as critical concerns.

Chapters

  1. 00:00Introduction to Anderson BCG Inspection
  2. 00:15Exterior Finish and Sharp Edges
  3. 01:43Gas Ring Test
  4. 01:50BCG Disassembly
  5. 02:31Firing Pin Inspection
  6. 03:06Firing Pin Protrusion Measurement
  7. 04:01Bolt Inspection: Tail, Shoulder, Lugs
  8. 05:01Extractor and Ejector Pin Check
  9. 05:34Firing Pin Hole Test
  10. 05:52Bolt Face Inspection
  11. 06:49Bolt Tail Gauge Test
  12. 08:16Cam Pin Inspection
  13. 09:45Cam Pin Fit in Bolt
  14. 12:07Magnetism Test
  15. 13:51Demagnetization Results
  16. 14:57Headspace Check
  17. 15:31Bolt Support Shoulder Measurement
  18. 15:49Carrier Length Measurement
  19. 16:22Carrier 3-Bore Gas Key Test
  20. 17:08Bolt Support Gas Seal Test
  21. 17:30Gas Ring Fit Test
  22. 17:40Bolt Tail Fit Test
  23. 18:36Overall Bolt Carrier Group Assessment
  24. 19:02Gas Key Inspection and Torque Test
  25. 20:49Internal Carrier Finish Inspection (Borescope)
  26. 22:45Final Conclusion and Summary

Frequently Asked Questions

What are common issues found in an Anderson Manufacturing bolt carrier group?

Common issues identified include sharp edges on the carrier exterior, short firing pin protrusion, erratic wear on the bolt lugs and shoulder, weak ejector spring tension, and a bolt tail that may be too small, leading to gas leakage. Magnetism in components and loose gas key screws are also potential problems.

How do you check for proper firing pin protrusion?

To check firing pin protrusion, you need to disassemble the bolt carrier group and measure the distance the firing pin extends from the bolt face. For .223/5.56 caliber, a minimum protrusion of .028 inches is generally recommended; measurements below this can indicate a faulty firing pin or bolt.

What causes gas leakage in a bolt carrier group?

Gas leakage can occur if the bolt tail is too small in diameter, allowing gas to bypass the seal against the carrier. Additionally, a loose or improperly staked gas key can also be a source of gas leaks, leading to cycling issues, especially with under-gassed systems or weaker ammunition.

Why is magnetism a concern in bolt carrier group components?

Magnetism in the firing pin, extractor, or bolt can cause reliability problems when shooting steel-cased ammunition or projectiles with bi-metal jackets. Material can shave off and stick to these magnetic components, leading to fouling and potential malfunctions.

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