Lee-Enfield No.4 Mk I

The No.4 Mk I featured a reinforced receiver and a heavier "floating" barrel, which significantly improved consistent accuracy over its predecessor. The most prominent innovation was the adoption of a receiver-mounted aperture sight, providing the infantryman with a longer and more intuitive sight radius compared to the older tangential sights.

During the conflict, the No.4 Mk I* variant was introduced, featuring a simplified bolt release through a notch in the bolt head track. This model became the standard variant for Canadian and American production, optimizing machining times without sacrificing the reliability of the Lee bolt action system.

The weapon became the symbol of the British and Commonwealth soldier on every front, from North Africa to the Burmese jungles and the Normandy landings. A trained soldier could exploit the fast bolt action to perform the "mad minute," maintaining a rate of fire superior to any other bolt-action rifle of the era.

Beyond its standard infantry role, the No.4 served as the basis for the No.4 Mk I (T) sniper rifle, equipped with the No.32 scope and selected for its exceptional barrel accuracy. This specialized version was extensively used by Allied snipers, remaining effective even in extreme environmental conditions thanks to the robustness of the Enfield action.

In the post-war era, the rifle saw the introduction of the No.4 Mk 2 version, featuring a trigger pivoted directly on the receiver rather than the trigger guard for improved pull consistency. Many existing weapons were updated to this standard, designated as Mk I/2 or Mk I/3 depending on the original version.

Although replaced by the semi-automatic L1A1 in 1957, the design survived for decades as the L42A1 sniper rifle chambered in 7.62 NATO. Today, the No.4 remains a military collecting icon and continues to serve in some paramilitary or ceremonial units, as well as being used by the Canadian Rangers until their recent transition to the C19.