Since the adoption of the 7.62x 51mm NATO in the late 1950s, only a limited number of special purpose Lee-Enfield rifles were produced. Generally converted No.4 actions, these are being designated as 4th generation.

Australian International Arms have manufactured the 5th generation of Lee-Enfield, for target shooting, military match and sporting markets. However, unlike the 4th generation, this is not a ‘converted’ Lee-Enfield. The AIA rifles are redesigned with modern techniques, but referencing more than a century of Lee-Enfield improvements and development... from Britain, North America and Australia.

The AIA project commenced in 1997, to make a large-magazine capacity bolt-action rifle. The concept... a new generation body with magazine adaptors for different cartridge lengths, incorporating the Brewer collar and barrel system and interchangeable bolt-head of uniform size (an advance on service Lee-Enfields with up to 5 different lengths). Concept calibres: 7.62x 39mm, 7.62x 51mm and 5.56x 45mm. For practicality, AIA decided upon the Lee, the most highly developed system with a century in service, production and production by leading factories on four different continents.

The No.4 Mk 2 was chosen as the most practical, given serviceability and accuracy of the 7.62mm L39A1 and Envoy. The first AIA prototype in 1998 used a No.4 body with proposed magazine adaptors and inter-changeable barrel and bolt-head. The new series was initially designated ‘No.4 Mk 10’.

In 1999, the next prototypes were new-made bodies with the 7.62x 39mm adaptor and featured the bolthead release catch behind the charger bridge like the original No.4 Mk I & Mk 2. This was then altered to the Savage and Long Branch Mk I* style with bolt-head release cut-out at the front, near the chamber.

The development concept advanced in parallel with British and North American Lee-Enfields and after testing and evolution through a number of body types, the end result for the M10 is a Lee-Enfield of the 21st century.

Over 60 years and millions of pounds spent in Lee-Enfield development, most improvements had already been incorporated in the British, Canadian, US and Australian manufacture. However, in a comparable search for the ‘ultimate’ bolt action, the new M10 has the advantage of contemporary CNC milling, forged steel receivers, full-floating barrel, a stronger charger bridge to stiffen the action, and a contemporary magazine case.

AIA’s original concept was to utilise some surplus No.4 parts, but it was found that most ‘new’ parts were rejects. The Model 10 is made entirely from new parts, using high grade steel and teak timber; no plastic, nylon or alloy. A heavier rifle, but as competition shooters and marksmen attest, they are more accurate.

The CIA/Woolwich hung trigger, Stevens-Savage bolt head release, early hinged outer bands, two-stage trigger, Lithgow cocking piece, dual L-aperture (Singer Mk I range adjustable leaf will fit), Long Branch safety lever and L42A1 sniper bedding plate on 7.62x 51mm models, are incorporated in AIA’s ‘new’ M10.