Forming some 300 Blackout brass

Published on November 29, 2021
Duration: 25:49

This video details a method for forming 300 Blackout brass from .223 Remington cases using a modified chop saw and a specialized jig. The process involves cutting the cases to a preliminary length, resizing them with a full-length die, and then trimming them to the correct 300 Blackout specifications. The instructor emphasizes the importance of proper jig adjustment and tool selection for achieving consistent results, while also demonstrating the subsequent steps of loading and testing the newly formed brass.

Quick Summary

To form 300 Blackout brass from .223 cases, use a modified chop saw with a jig for initial cuts, then resize with a full-length die and trim to 1.368 inches. Reloading involves using powders like Alliant Power Pro 300 MP with 110-grain bullets, aiming for a 2.050-inch overall length.

Chapters

  1. 00:00Introduction & Goal: Forming 300 Blackout Brass
  2. 01:04Chop Saw Setup with Elite 3D Designs Jig
  3. 03:00Initial Burring and Length Check
  4. 03:48Resizing with Redding Full Length Die
  5. 05:00Adjusting Chop Saw Jig for Correct Length
  6. 06:15Re-cutting and Measuring Brass Length
  7. 07:26Troubleshooting Jig Adjustments
  8. 07:54Achieving Correct Preliminary Length
  9. 10:16Final Trimming with Case Trimmer
  10. 11:10Lee Trimmer Results
  11. 11:38Five Formed Cases Ready for Loading
  12. 12:22Checking Fit in Firearm
  13. 13:16Preparing to Load: Wiping Lube, Bullet & Powder Choice
  14. 14:32Powder Measurement with Lee Deluxe Perfect Powder Measure
  15. 17:39Seating 110gr Hornady Z-Max Bullets
  16. 18:59Shooting Five Formed Rounds
  17. 19:21Post-Firing Brass Inspection
  18. 20:49Zeroing Scope and First Shots
  19. 21:23Firearm Specs: 16" Wilson Combat Barrel
  20. 21:34Shooting a Five-Shot Group
  21. 22:32Initial Group Results and Analysis
  22. 24:05Final Ballistics Data and Group Size
  23. 24:47Review of Chop Saw Jig Performance
  24. 25:35Conclusion and Future Plans

Frequently Asked Questions

What tools are needed to form 300 Blackout brass from .223 cases?

You'll need a modified chop saw with a specialized jig (like those from Elite 3D Designs), a reloading press, a full-length sizing die (e.g., Redding), a case trimmer (e.g., Lee or Frankfort Arsenal), and lubricants like Imperial sizing die wax.

What is the correct trim length for 300 Blackout brass?

The maximum recommended trim length for 300 Blackout brass is 1.368 inches. This allows for a small margin for case mouth preparation after resizing and trimming.

What powder and bullet combination was tested for the formed 300 Blackout brass?

The formed brass was loaded with 110-grain Hornady Z-Max bullets and Alliant Power Pro 300 MP powder, with a starting charge of 20.1 grains. The overall cartridge length was set to 2.050 inches.

What were the ballistics results for the reloaded 300 Blackout ammunition?

The tested loads averaged 2337 fps with a standard deviation of 19.5 and an extreme spread of 64 fps. The group size was approximately 2.79 inches over 24 shots at 100 yards.

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