Introduction to the 40mm Bofors anti-aircraft gun: was a weapon widely used during World War II. It has an effective range of 7200 meters and a firing arc of -5° to +90°. The gun was first launched in Sweden in 1930 and was used in 19 countries by 1938. Some countries produced and exported it to other places after modifying the original plans. On display here is the standard medium-sized anti-aircraft gun used by the British Army from 1930 to 1970. In 1941, the British Army in Hong Kong was also equipped with this weapon.