.357 Magnum - Powder Coated 158gr SWC in the Henry Big Boy

Published on February 4, 2017
Duration: 19:22

This guide details the process of reloading .357 Magnum cartridges using 158-grain powder-coated semi-wadcutter (SWC) bullets and Unique powder in a Henry Big Boy rifle. The presenter, Johnny, walks through preparing brass, charging with powder, seating bullets to a specific depth, and crimping. He aims for an overall length of approximately 1.585 inches and uses 5.0 grains of Unique powder, a load he selected based on various sources, noting potential confusion with published data. The process emphasizes careful seating and crimping to ensure proper function in the rifle.

Quick Summary

Reloading .357 Magnum with 158-grain powder-coated SWC bullets involves preparing brass, charging with 5.0 grains of Unique powder, and seating bullets so the top lube groove is at the case mouth for an overall length of ~1.585 inches. Winchester small pistol magnum primers are used, and the reloaded cartridges achieved approximately 1103 ft/s with outstanding accuracy.

Chapters

  1. 00:01Introduction and Goal
  2. 00:21Bullet Preparation and Casting Issues
  3. 01:41Powder Selection and Load Data
  4. 02:44Bullet Seating and Crimping Groove
  5. 03:21Brass Preparation and Priming
  6. 05:01Powder Charging
  7. 05:18Bullet Seating Process
  8. 06:43Overall Length Measurement
  9. 07:33Crimping Process
  10. 08:39Finished Reloaded Cartridges
  11. 09:08Reloading Summary and Range Prep
  12. 10:09Range Setup and Chronograph
  13. 10:42Loading the Henry Big Boy Magazine
  14. 11:32First Shot and Velocity Reading
  15. 12:14Group Shooting
  16. 13:15Initial Range Results Analysis
  17. 13:37Shooting Steel Plates
  18. 14:24100 Yard Steel Plate Challenge
  19. 16:39Adjusting Target Distance
  20. 17:14Final Reloads and Bore Inspection
  21. 18:34Concluding Steel Plate Shooting
  22. 19:01Post-Shoot Inspection and Conclusion

Frequently Asked Questions

What is the recommended load for .357 Magnum with 158-grain bullets in a rifle?

For .357 Magnum with 158-grain lead bullets in a rifle, the presenter uses 5.0 grains of Unique powder. This load is towards the upper end of published data, aiming for velocities around 1100 ft/s, but always consult your specific reloading manual for safe and accurate load data.

How do you seat 158-grain semi-wadcutter bullets for .357 Magnum?

When seating 158-grain semi-wadcutter (SWC) bullets for .357 Magnum, the goal is to position the top lube groove approximately at the case mouth. This typically results in an overall cartridge length of around 1.585 inches, ensuring proper chambering and function.

What are the key steps in reloading .357 Magnum with powder-coated bullets?

Reloading .357 Magnum involves preparing brass (sizing, priming, flaring), charging with powder (5.0 grains of Unique in this case), seating the powder-coated 158gr SWC bullets to the correct depth, and applying a factory crimp. Ensure all components are compatible and follow safe reloading practices.

What kind of primers are used for .357 Magnum reloads with Unique powder?

The presenter uses Winchester small pistol magnum primers for their .357 Magnum reloads. While Unique powder is generally easy to ignite and might not strictly require a magnum primer, using them consistently is a common practice for magnum cartridges.

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