Belted 6 ARC issue

Published on March 14, 2022
Duration: 19:14

This video details the process of forming 6mm ARC brass from 6.5 Grendel brass, highlighting a peculiar 'belted' ring formation at the case head, potentially linked to over-pressure and the use of small base sizing dies. The instructor experiments with different dies and brass types, firing reloaded cartridges to observe and analyze these pressure signs, ultimately suggesting that avoiding high pressure is key to preventing this issue.

Quick Summary

A 'belted' ring on 6mm ARC brass formed from 6.5 Grendel is often a sign of high pressure, potentially worsened by small base sizing dies. These dies can shrink the case body, pushing excess brass to the base. While concerning, this deformation may not lead to case head separation but indicates pressure is nearing limits. Using standard dies and managing powder charges are recommended.

Chapters

  1. 00:00Introduction: Belted Brass Issue
  2. 00:24Visualizing the Belted Ring
  3. 01:10Comparing Virgin vs. Formed Brass
  4. 02:11Case Head Deformation Analysis
  5. 02:37Investigating the Cause: Sizing Dies
  6. 03:00Measuring Sizing Die Differences
  7. 03:34Hypothesis: Small Base Die & Excess Brass
  8. 04:05Testing Plan: Different Brass & Loads
  9. 05:117.62x39 Brass Observations
  10. 05:28Forming with Hornady Die & Different Brass
  11. 06:14Sizing Lapua & Hornady Brass
  12. 07:58Annealing Impact on Sizing
  13. 09:00Resizing Previously Formed Brass
  14. 09:47Trimming and Expanding
  15. 10:09Loading with Reloader 15.5
  16. 11:20Bullet Selection for Testing
  17. 12:34Post-Firing Brass Inspection
  18. 13:04Starline Brass Results
  19. 13:26Hornady Brass Results
  20. 14:00Lapua Brass Results (Pre-Fire)
  21. 14:267.62x39 Brass Results (Primer Popped)
  22. 14:55Lapua 220 Russian Results
  23. 15:17Conclusions & Next Steps
  24. 15:50Testing Starline Brass Over Multiple Firings
  25. 16:16Second Firing Results
  26. 16:26Third Firing Results
  27. 16:34Fourth Firing Results
  28. 16:40Fifth/Sixth Firing Results
  29. 17:10Long-Term Strategy for Problem Brass
  30. 17:35Recommendation: Form New Brass with Standard Dies
  31. 18:14Summary of Findings & Future Considerations
  32. 18:23Preference for Factory 6mm ARC Brass
  33. 18:42Final Thoughts & Viewer Engagement

Frequently Asked Questions

What causes a 'belted' ring on 6mm ARC brass formed from 6.5 Grendel?

A 'belted' ring on 6mm ARC brass formed from 6.5 Grendel is often caused by high pressure during firing, potentially exacerbated by the use of small base sizing dies. These dies may shrink the case body excessively, pushing excess brass down to the base and creating the visible ridge.

Are small base dies problematic for forming 6mm ARC brass?

Small base dies, like the RCBS set, can contribute to case deformation and the 'belted' ring issue when forming 6mm ARC brass. Using a standard sizing die may yield better results with less pronounced deformation, as observed in testing.

What are the signs of over-pressure in 6mm ARC reloading?

Signs of over-pressure in 6mm ARC reloading include a 'belted' ring formation at the case head, excessive case head expansion, difficult extraction, popped primers, and potentially difficult chambering of rounds. It's crucial to monitor these indicators.

Does the type of brass affect 6mm ARC forming issues?

Yes, the type of brass can influence 6mm ARC forming issues. Lapua brass, for instance, showed early signs of the ridge even before fire-forming. Brass from 7.62x39 also exhibited more pronounced deformation and higher pressures due to its smaller case capacity.

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