AAC BCG Physical

Published on April 14, 2020
Duration: 11:45

This video provides a detailed physical inspection and partial disassembly of an Advanced Armament Company (AAC) Bolt Carrier Group (BCG). The instructor examines the nickel boron and phosphate components, checks staking, and performs various tests including gas ring fit, bolt protrusion, and magnetism. The borescope inspection reveals some machining marks and inefficiencies in the gas ring area, offering insights into potential wear patterns and manufacturing quality.

Quick Summary

The AAC Bolt Carrier Group (BCG) features a nickel boron coated carrier and a phosphate coated bolt. While the carrier finish is smooth, a borescope inspection revealed machining marks in the three-bore area and a rough bolt tail. Gas ring efficiency tests indicated slight inefficiencies, suggesting potential wear or manufacturing tolerances that could impact performance.

Chapters

  1. 00:00Introduction to AAC BCG Physical Inspection
  2. 00:21Initial Staking and Fastener Check
  3. 00:43Carrier Modifications and Gas Ring Test
  4. 01:09Disassembly: Firing Pin and Cam Pin Removal
  5. 01:26Bolt and Carrier Finish Analysis
  6. 01:51Extractor Inspection: O-ring, Insert, and Spring
  7. 03:01Extractor Functionality and Magnetism Test
  8. 03:08Firing Pin Tip and Protrusion Check
  9. 03:59Ejector Inspection and Bolt Face Check
  10. 04:52Cam Pin and Bolt Tail Dimensions
  11. 05:07Headspace and Support Ring Measurement
  12. 06:48Carrier Length and SK Alignment
  13. 07:32Gas Path and Gas Key Seal Test
  14. 07:48Gas Key Screw Torque Check
  15. 08:35Borescope Inspection: Three Bore and Gas Rings
  16. 09:47Borescope Inspection: Bolt Tail
  17. 10:15Gas Ring and Bolt Tail Gauge Testing
  18. 11:15Overall Assessment of AAC BCG

Frequently Asked Questions

What are the primary materials and finishes of the AAC Bolt Carrier Group inspected?

The AAC Bolt Carrier Group (BCG) features a nickel boron coated carrier, known for its smooth finish, and a phosphate coated bolt. The nickel boron finish on the carrier is generally well-regarded for its appearance and durability.

How is the staking and fastener quality assessed on this AAC BCG?

The staking on this particular AAC BCG is described as 'ok' and not excessively heavy. It does not utilize YFS fasteners, which are often considered a higher quality option in some firearm components.

What were the key findings from the borescope inspection of the AAC BCG?

The borescope inspection revealed some inconsistencies and machining marks in the carrier's three-bore area, especially near the gas ring run. The bolt tail was also noted as being 'pretty rough' and not cleanly finished.

What tests were performed to evaluate the gas ring and bolt tail fit on the AAC BCG?

Gas ring efficiency and bolt tail seal were tested using specialized gauges. The results indicated slight inefficiencies, with some gauges passing 'barely' or 'with ease', suggesting a less than optimal seal in these areas.

Related News

All News →

More Gunsmithing & DIY Videos You Might Like

More from School of the American Rifle

View all →