Redding Mandrels vs No Mandrels: The Data Doesn’t Lie

Published on February 18, 2026
Duration: 16:03

This video demonstrates the use of Redding's Precision Expanding Die and mandrels to achieve consistent neck tension in rifle brass. By using mandrels, reloaders can precisely control the internal neck diameter, leading to more uniform bullet seating forces. This process is shown to significantly reduce variability in bullet seating, which directly impacts ballistic consistency, extreme spread, and standard deviation in velocity, ultimately improving rifle cartridge performance.

Quick Summary

Consistent neck tension is vital for precision rifle reloading, impacting SD, ES, and accuracy. Redding's Precision Expanding Die and mandrels allow for precise control of case neck diameter, creating uniform bullet seating forces. This process significantly reduces variability, leading to tighter velocity spreads and improved ballistic performance, while also preventing bullet damage.

Chapters

  1. 00:05Importance of Neck Tension
  2. 00:21Introducing Redding's Precision Expanding Die
  3. 00:30Why Neck Tension Matters
  4. 01:50Mandrel Dies vs. Expander Balls
  5. 02:06Redding's New Die and Mandrel System
  6. 02:13Mandrel Size Options
  7. 02:46Die Setup Overview
  8. 03:23Setting Up the Die on the Press
  9. 03:47Putting the Die to the Test
  10. 03:52Testing 6 GT Brass
  11. 04:24Applying Graphite Lube
  12. 05:18Mandreled vs. Non-Mandreled Brass
  13. 05:32AMP Press Setup for Testing
  14. 05:46Measuring Neck Diameters
  15. 06:16Applying Mica Lube for Comparison
  16. 06:31Bullet Seating Force Test - Non-Mandreled
  17. 08:06Initial Results: Non-Mandreled Brass
  18. 08:29Bullet Seating Force Test - Mandreled Brass
  19. 09:42Final Results: Mandreled vs. Non-Mandreled
  20. 10:09Meaning of Consistent Neck Tension
  21. 10:32Testing .22 Caliber Results
  22. 11:00Preparing .223 Remington Brass
  23. 11:38Results: Non-Mandreled .223 Remington
  24. 11:54Results: Mandreled .223 Remington
  25. 12:41Comparing Peak Forces
  26. 13:13Conclusion on Mandreling Necks
  27. 13:31Available Calibers and Mandrel Options
  28. 14:14Impact on Bullet Seating Behavior
  29. 14:34Benefits for Shooting Consistency
  30. 14:40Final Thoughts on Redding Dies
  31. 15:00Viewer Feedback Request
  32. 15:11More Redding Content Coming
  33. 15:15Video Wrap-up
  34. 15:21Ultimate Reloader Resources

Frequently Asked Questions

What is neck tension in reloading and why is it important?

Neck tension in reloading refers to the interference fit between the bullet and the case neck. It's crucial for precision rifle cartridges because it ensures the bullet is held securely and consistently, which directly impacts muzzle velocity consistency (SD/ES) and overall accuracy. Too much or too little tension can lead to poor performance.

How do Redding's Precision Expanding Dies and mandrels improve reloading?

Redding's system uses interchangeable mandrels to precisely size the inside diameter of the case neck. This creates a consistent interference fit with the bullet, leading to much smoother and more uniform bullet seating forces. This consistency translates to tighter velocity spreads and improved ballistic performance.

What are the benefits of using mandrels for neck sizing compared to traditional expander balls?

Mandrels provide a more controlled and precise way to size case necks, ensuring a uniform diameter. Traditional expander balls can vary in their effect and may not achieve the same level of consistency. Mandreling leads to lower, smoother bullet seating forces and prevents damage to bullets, preserving ballistic coefficient.

What range of neck tension can be achieved with Redding's mandrels?

Redding offers mandrels in half-thou increments for each caliber. They typically start at 0.5 thou under the bullet diameter and go down to 3 thou under. This allows reloaders to fine-tune neck tension for optimal bullet retention and seating consistency.

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