Navy M1 Garand Conversions to 7.62mm NATO: Mk2 Mod0 & Mk2 Mod1

Published on May 9, 2026
Duration: 10:40

This video details the US Navy's conversion of M1 Garand rifles to 7.62mm NATO, specifically the Mk2 Mod0 and Mk2 Mod1 variants. It explains the technical challenges, the initial bushing method's failures, and the eventual adoption of new barrels. The content is presented by Ian McCollum of Forgotten Weapons, offering expert insights into the historical firearms modification process.

Quick Summary

The US Navy converted M1 Garand rifles to 7.62mm NATO, initially using a problematic chamber bushing (Mk2 Mod0) that frequently failed. The Mk2 Mod1 variant replaced these with new Springfield Armory barrels. These conversions were primarily for training and competition, facing significant reliability issues and a 'comedy of errors' development path.

Chapters

  1. 00:05Introduction to Navy M1 Garand Conversions
  2. 00:32US Army's Decision Against Conversion
  3. 01:40Navy's Decision to Convert M1 Garands
  4. 02:24The Mk2 Mod0 Conversion: Chamber Bushing
  5. 03:05Springfield Armory's Negative Feedback on Bushings
  6. 03:33AMF and H&R Conversions
  7. 04:07Naval Weapons Facility Crane's Fix Attempts
  8. 04:35The Mk2 Mod1 Conversion: New Barrels
  9. 05:13Identifying the Mk2 Mod1: Receiver Markings
  10. 05:23Magazine Well Spacer and Safety Features
  11. 06:20Gas Port Adjustment
  12. 06:35Identifying Mk2 Mod0 Barrels (H&R)
  13. 07:22Identifying Mk2 Mod1 Barrels (AMF)
  14. 07:56Springfield 7.62mm Barrel Drawing Numbers
  15. 08:27Program Analysis: Comedy of Errors
  16. 09:15Risk of Fakes and Forgeries
  17. 10:05Authenticity and CMP Provenance
  18. 10:25Conclusion and Thanks

Frequently Asked Questions

Why did the US Navy convert M1 Garand rifles to 7.62mm NATO?

The US Navy converted M1 Garands to 7.62mm NATO primarily for ammunition standardization and to avoid being low priority for the newer M14 rifles. This allowed them to use the common NATO round while retaining a familiar and reliable platform.

What were the two main methods used by the US Navy to convert M1 Garands to 7.62mm NATO?

The initial method, the Mk2 Mod0, involved inserting a chamber bushing to adapt the existing .30-06 chamber for 7.62mm NATO. This proved unreliable as the bushings often came loose. The later Mk2 Mod1 conversion replaced the bushing with entirely new Springfield Armory barrels chambered in 7.62mm NATO.

How can one identify a genuine US Navy converted M1 Garand?

Genuine conversions often have specific markings on the barrel indicating the manufacturer (AMF, H&R) and caliber (7.62 NATO). Mk2 Mod1 rifles will have new Springfield barrels with specific drawing numbers and production dates. The presence of a chamber bushing is characteristic of the Mk2 Mod0, though these are prone to issues.

What were the main problems with the US Navy's M1 Garand conversion program?

The program suffered from a flawed initial design (loose chamber bushings), ignored warnings from testing facilities, and ultimately a costly solution that saw limited actual service use. The rifles were mostly relegated to training and competition roles.

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