2 Young Manufacturing BCG Physicals

Published on April 3, 2020
Duration: 26:19

This video provides an in-depth physical inspection of two Young Manufacturing Bolt Carrier Groups (BCGs), one standard and one National Match. The instructor, from the School of the American Rifle, meticulously examines various components, including the carrier, bolt, firing pin protrusion, cam pin, extractors, and gas key alignment. Several potential issues are identified, such as short firing pin protrusion on one bolt and gas key alignment problems on the standard carrier, highlighting the importance of detailed inspection for optimal firearm function.

Quick Summary

This video details a physical inspection of two Young Manufacturing Bolt Carrier Groups (BCGs), one standard and one National Match. Key findings include short firing pin protrusion on the National Match bolt and gas key alignment issues on the standard carrier. The instructor highlights differences in rail design, fastener types, and internal finishes, emphasizing the importance of thorough inspection for AR-15 components.

Chapters

  1. 00:00Introduction to Young Manufacturing BCGs
  2. 00:55Initial Disassembly and Gas Ring Test
  3. 01:13Carrier Inspection (Standard and NM)
  4. 02:30Firing Pin Retaining Pin Check
  5. 02:48Firing Pin and Bolt Removal
  6. 03:27Importance of Cleaning for Inspection
  7. 04:00Bolt Design Observation
  8. 04:33Bolt Inspection: Extractor Removal
  9. 05:09Extractor Finish Comparison
  10. 05:18Extractor Movement and Gauge Test
  11. 06:32Magnetism Test
  12. 07:25Firing Pin Hole and Protrusion Check
  13. 08:00Firing Pin Protrusion Measurement (NM)
  14. 09:09Firing Pin Protrusion Measurement (Standard)
  15. 11:52Cam Pin Inspection
  16. 12:42National Match Bolt Roll Pin and Gas Rings
  17. 13:08Bolt Shoulder Support Measurement
  18. 14:58Bolt Face Inspection
  19. 15:35Ejector Inspection
  20. 15:53Magnetism Check and Headspace Test
  21. 16:03.223 Go Gauge Test
  22. 16:125.56 Go Gauge Test
  23. 16:56No-Go Gauge Test
  24. 17:20Carrier Inspection: Gas Key Alignment
  25. 17:40Gas Key Alignment Issues (Standard)
  26. 18:00Gas Key Alignment (National Match)
  27. 19:26Gas Key Dimension Check
  28. 19:32Gas Key Gauge Test (Standard)
  29. 19:38Gas Key Gauge Test (National Match)
  30. 20:15Obstruction Check
  31. 20:27Carrier Length Check
  32. 20:51Reverse Torque Test Setup
  33. 21:11Reverse Torque Test (Standard)
  34. 21:39Reverse Torque Test (National Match)
  35. 22:25Carrier Three Bore Check
  36. 22:27Bolt Shoulder Support Gauge Check (Standard)
  37. 22:42Bolt Shoulder Support Gauge Check (National Match)
  38. 23:02Gas Ring Run Gauge Check
  39. 23:29Bolt Tail Gauge Check
  40. 24:11Borescope Inspection Preparation
  41. 25:01Borescope Inspection (National Match)
  42. 25:34Borescope Inspection (Standard)
  43. 26:01Conclusion and Summary of Findings

Frequently Asked Questions

What are the key differences between a standard and a National Match Young Manufacturing BCG?

The National Match (NM) BCG features slightly wider dimensions and beefier carrier rails for increased contact surface with the upper receiver. The standard model has protruding rails, while the NM has rails integrated into the main surface. Both use YFS fasteners and are not staked.

What issues were found with the firing pin protrusion on the Young Manufacturing BCGs?

The National Match bolt exhibited firing pin protrusion at the bare minimum (0.028 inches) and sometimes too short (0.025-0.026 inches), indicating a potential bolt issue. The standard BCG was at the minimum acceptable range (0.0285 inches).

Are Young Manufacturing BCGs staked?

No, Young Manufacturing does not stake their gas keys, relying on thread locker instead. This is a known characteristic of their products, though it can be a concern for heavy use applications where heat might affect the thread locker's integrity.

What was the result of the gas key alignment test on the Young Manufacturing BCGs?

The standard carrier showed alignment issues with the gas key, potentially causing wear on the gas tube. The National Match carrier's alignment was tighter and passed the alignment test more effectively.

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