A New Enfield for a New War: The No4 MkI

Published on July 7, 2021
Duration: 19:28

This entry details the Lee-Enfield No. 4 Mk I, the standard British service rifle of WWII, tracing its development from earlier models and highlighting key design changes. It covers nomenclature shifts, mechanical improvements like aperture sights and heavier barrels, the iconic spike bayonet, and production details from major factories. Expert Ian McCollum provides a deep dive into its evolution and significance.

Quick Summary

The Lee-Enfield No. 4 Mk I, the standard British service rifle of World War II, evolved from earlier models with key improvements like a heavier barrel for accuracy, a stronger receiver, and a micrometer-adjustable rear sight. Its development was notably delayed by a decade due to military priorities, and it featured a distinctive 8-inch cruciform spike bayonet.

Chapters

  1. 00:00Introduction to the No. 4 Mk I
  2. 00:40Post-WWI Development
  3. 02:00Nomenclature Changes
  4. 03:01Mechanical Comparisons
  5. 03:51Receiver Markings
  6. 04:37Front Band and Sight Features
  7. 05:53Muzzle Design and Accuracy
  8. 07:04The Spike Bayonet
  9. 08:57Trials Patterns A, B, and C
  10. 10:39Accuracy and Sights
  11. 11:36Production Simplification
  12. 13:09Manufacturing Factories
  13. 14:30The 10-Year Gap
  14. 16:08Fate of Trials Rifles

Frequently Asked Questions

What distinguished the Lee-Enfield No. 4 Mk I from earlier models like the No. 1 Mk III*?

The No. 4 Mk I introduced significant design changes, including a heavier barrel for accuracy and grenade launcher mounting, a high receiver wall for strength, and a micrometer-adjustable rear aperture sight, moving away from the SMLE's traditional design.

Why was there a ten-year gap between the No. 4 Mk I trials and its mass production?

The delay was primarily due to the British government's focus on developing self-loading rifles and prioritizing the production of Bren guns. These factors, combined with ongoing experimentation, pushed the No. 4 Mk I's widespread adoption to the eve of World War II.

What was the purpose of the 8-inch cruciform spike bayonet on the No. 4 Mk I?

The cruciform spike bayonet was designed to be lighter and more combat-effective than the older sword bayonets. Its four-sided blade reduced weight and minimized the risk of bending or breaking during close-quarters combat.

Which factories were the primary producers of the Lee-Enfield No. 4 Mk I?

The main production facilities for the No. 4 Mk I in the United Kingdom were the Royal Ordnance Factory Maltby (ROFM), the Royal Ordnance Factory Fazakerley (ROFF), and the Birmingham Small Arms Company (BSA) Shirley. Maltby was the first to pass inspection.

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