M855A1 Reloading Test

Published on April 18, 2021
Duration: 45:13

This video details the process of disassembling M855A1 ammunition to analyze its components and then uses those components for reloading experiments. The instructor demonstrates bullet pulling techniques, powder charge analysis, and bullet measurements. Reloading tests are conducted with different powders and bullets, followed by live-fire accuracy and velocity testing. The analysis highlights the challenges and potential outcomes of reloading with military surplus components.

Quick Summary

The M855A1 is the US military's current 5.56 general purpose round (EPR), replacing the M855. Its lead-free design and larger diameter reduce case capacity, making reloading with standard data dangerous due to high pressures. Reloading tests with M855A1 bullets yielded groups between 1.5-2.5 inches, with the best 10-shot group at 1.52 inches.

Chapters

  1. 00:00Introduction to M855A1
  2. 00:05M855A1 Overview & Previous Accuracy Test
  3. 01:08Plan: Reloading M855A1 Components
  4. 01:48Bullet Pulling Process
  5. 03:03Bullet Puller Issues & Workarounds
  6. 04:30Detailed Bullet Pulling Steps
  7. 05:20Collecting Powder & Bullet
  8. 05:35M855A1 Bullet Sealant Analysis
  9. 06:15Powder Charge Weight Analysis
  10. 07:07Powder Characteristics
  11. 07:26Powder Charge Weight Distribution
  12. 08:06Identified Powder: SMP842/WC-842
  13. 08:30Bullet Cleaning & Inspection
  14. 09:44Bullet Weight & BTO Measurements
  15. 11:12Bullet Base to Ogive Variation
  16. 12:08Sorting Bullets by BTO
  17. 12:52Reloading Plan: Hornady Bullets
  18. 13:33Reloading Plan: M855A1 Bullets & Powders
  19. 14:34Bullet Size Comparison: M855A1 vs. Hornady
  20. 15:11Case Capacity Implications
  21. 16:01Overall Length & Rifling Jump
  22. 16:40Measuring Rifling Jump
  23. 17:53Seating Depth Plans Adjusted
  24. 18:29Bullet Seating Die Selection
  25. 19:40Testing Various Seating Dies
  26. 20:20Frankford Arsenal Universal Seating Die
  27. 21:27Bullet Seating Plan Finalized
  28. 21:38Setting Up the Press & Seating Die
  29. 22:17Brass & Primer Selection
  30. 22:33Seating Hornady Bullets
  31. 24:44Seating Die Performance Notes
  32. 25:34Seating M855A1 Bullets
  33. 29:00Cartridge Base to Ogive Measurement
  34. 31:30Range Test Setup
  35. 31:53Test 1: Hornady Bullets
  36. 33:39Hornady Bullet Group Results
  37. 34:43Hornady Bullet Velocity Statistics
  38. 36:03Test 2: M855A1 Bullets w/ Power Pro Varmint
  39. 37:13Power Pro Varmint Group Results
  40. 37:44Test 3: M855A1 Bullets w/ AR Comp
  41. 39:51AR Comp Group Results
  42. 41:25Test 4: M855A1 Bullets w/ IMR 8208 XBR
  43. 42:23IMR 8208 XBR Initial Group Results
  44. 43:37IMR 8208 XBR Final Group Results
  45. 44:35Conclusion: M855A1 Reloading Limitations
  46. 44:51Final Thoughts & Bench Return

Frequently Asked Questions

What is the M855A1 round and why is it significant for reloaders?

The M855A1 is the current US military's 5.56 general purpose round, known as the Enhanced Performance Round (EPR). It's significant because it's not readily available on the commercial market, making its components desirable for reloaders seeking to experiment with military-grade ammunition.

What are the key challenges when reloading with M855A1 bullets?

M855A1 bullets have a lead-free core and a larger diameter than standard lead-core bullets, significantly reducing case capacity. This means standard load data can lead to dangerously high pressures. Additionally, their sealant and potential inconsistencies in manufacturing can affect seating and accuracy.

What powder is likely used in M855A1 ammunition?

Based on analysis, the powder used in M855A1 rounds is likely SMP842 or WC-842, which is a standard ball powder. Extracted charges typically ranged between 26.4 and 26.8 grains, with 26.7 grains being the most common.

What were the accuracy results when reloading M855A1 bullets?

Reloading M855A1 bullets with various powders (Power Pro Varmint, AR Comp, IMR 8208 XBR) and the extracted military powder resulted in groups generally ranging from 1.5 to 2.5 inches at 100 yards. The best 10-shot group achieved was 1.52 inches with IMR 8208 XBR.

How does the M855A1 bullet compare in size to a standard 62-grain bullet?

The M855A1 bullet is noticeably larger and less dense than a typical 62-grain lead-core bullet like the Hornady HPBT. This size difference means the M855A1 bullet protrudes further into the case, reducing the available volume for powder and increasing pressure.

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