Black Rifle Arms C.A.P.S. External Piston Rifle - How to make a 7.62x39mm AR work reliably

Published on March 2, 2021
Duration: 40:19

This video details how to achieve reliable function in an AR-15 platform chambered in 7.62x39mm, addressing historical issues like feeding failures and light strikes. It highlights specific modifications including upgraded firing pins, heavier hammer springs, and specialized magazines. The Black Rifle Arms C.A.P.S. external piston system is showcased as a solution for adjustable gas management, crucial for diverse ammunition types and suppressed fire.

Quick Summary

Making a 7.62x39mm AR-15 reliable involves addressing feeding issues with specialized magazines like Duramag or D&H Tactical, and fixing light strikes by upgrading to a 7.62x39mm firing pin and a heavier hammer spring. An adjustable gas system, such as the Black Rifle Arms C.A.P.S., is also vital for managing diverse ammunition pressures.

Chapters

  1. 00:08Introduction: 7.62x39mm AR-15 Challenges
  2. 00:33Historical Context: Colt's 7.62x39mm ARs
  3. 01:31Magazine Well Design vs. Cartridge Taper
  4. 02:38Ammunition Pressure Issues
  5. 03:20Addressing Feeding Issues: Early Magazines
  6. 04:07Introduction to Black Rifle Arms C.A.P.S. System
  7. 06:18Magazine Solutions: Duramag & D&H Tactical
  8. 07:37Full Auto Magazine Testing
  9. 09:11Magazine Test Results & Recommendations
  10. 10:13Addressing Light Strike Issues
  11. 10:32Firing Pin Impression Differences
  12. 11:30Standard AR-15 Firing Pins vs. 7.62x39mm
  13. 12:02Firing Pin and Hammer Spring Modifications
  14. 13:23Demonstration: Standard vs. Modified Firing Pin
  15. 17:34Broken Extractors and Bolts
  16. 18:40Enhanced Bolts and Extractors
  17. 20:05Alternative: ARs with AK Magazines
  18. 20:37Ammunition Reliability and Gas System Needs
  19. 21:217.62x39mm Ammunition Variability
  20. 24:49Black Rifle Arms C.A.P.S. System Deep Dive
  21. 25:15C.A.P.S. Adjustable Gas Valve Explained
  22. 26:20Internal Components: Buffer and Hammer Spring
  23. 27:43Bolt Carrier with Polymer Butt
  24. 29:007.62x39mm Bolt vs. 5.56 Bolt
  25. 30:34C.A.P.S. Gas System Disassembly
  26. 32:39Suppressor Considerations
  27. 33:23Range Test: Gecco Ammunition
  28. 35:28Range Test: Tula Ammunition
  29. 37:06Range Test: Hornady SST Ammunition
  30. 37:35Conclusion: Reliable 7.62x39mm AR-15 Achieved
  31. 38:08Final Thoughts on Duramag and Platforms
  32. 39:06C.A.P.S. System Performance Review
  33. 39:48Buffer Recommendations for External Piston Systems
  34. 40:13Outro and Call to Action

Frequently Asked Questions

What are the main issues with making an AR-15 reliable in 7.62x39mm?

The primary issues are feeding reliability due to the AR-15's straight magazine well not matching the tapered 7.62x39mm cartridge, and ignition problems caused by harder primers in Russian ammunition. Broken extractors and bolts are also common due to increased stress.

How can light strike issues be fixed in a 7.62x39mm AR-15?

Light strikes can be fixed by replacing the standard AR-15 firing pin with one designed for 7.62x39mm, which is often longer and has a different tip shape. Additionally, installing a heavier hammer spring provides more force to reliably ignite harder primers.

What magazines are recommended for a reliable 7.62x39mm AR-15 build?

For reliable feeding, Duramag (specifically their 28 or 30-round magazines) and D&H Tactical magazines are highly recommended. These have proven effective in addressing the feeding challenges inherent in chambering 7.62x39mm in an AR-15 platform.

What is the Black Rifle Arms C.A.P.S. system and why is it useful for 7.62x39mm AR-15s?

The C.A.P.S. (Combat Adaptive Piston System) is an external piston upper receiver with a four-position adjustable gas block. This adjustability is crucial for tuning port pressure to reliably cycle various types of 7.62x39mm ammunition, especially with suppressors, and to compensate for fouling.

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