Australian made during the early Pacific phase of WWII, this model probably completed in 1942, unknown service during the war and after.  From the lack of modifications, it was retired to war reserves about 1950 to 1952.

Ordnance the ID plate is missing, it is unknown whether it is Mk I or Mk I*.  The barrel was made by the ROF Enfield. It is fitted with the fabricated elevating arc M2/AN9476.

Mounting Mk 4/2 (Australian).  Most fittings for electric drive have been removed but the mounting plates on the operator platform are still present.

Platform Mk 2 (Australian).  The H bar to secure the gun during transport has been replaced with the A-frame.

In the early 1930’s the 40 mm gun was developed for defence against low flying aircraft by the Swedish Armament Manufacturer ‘Bofors’. The 40mm Bofors was an extremely versatile gun. Apart from its prime role it was used as an anti-tank weapon, against torpedo-boats in harbour defence, in neutralising fire during infantry assaults, for attacking fortified bunkers, shooting up enemy transport and indicating lines and timing of infantry advance at night.

When the 2nd AIF arrived in the Middle East two of the Anti Aircraft Regiments were trained on and issued with 40 mm Bofors guns. On their return to Australia they brought their guns with them in most cases providing the Anti Aircraft protection for their transport ships.

The Army in Australia was issued with the 40 mm Bofors gun in late 1941 and gradually batteries were built up and sent to areas where they might be required. These batteries and those of the AIF saw action in all theatres of the war, in Darwin and the South West Pacific Area.