The 40mm Bofors has become the quintessential anti-aircraft artillery piece of WWII — perhaps of the 20th century. The 40mm Bofors was developed in Sweden beginning in 1929, and by 1932 the design had been perfected. After firing a 1.96-lb shell to a vertical range of 4.3 miles with at an average rate of 80-100 rounds per minute in the Spanish Civil War, the weapon drew the attention of armed forces world-wide.

Accordingly, the U.S. Army in May 1937 sought to obtain a test gun from Aktiebolaget Bofors (AB Bofors). The reply from the firm read in part, “…we are unfortunately not in a position to provide…the materiel asked for, as we on principle do not sell guns and ammunition for demonstration purposes.”

However, the Chief of the Coast Artillery, Major A. H. Sunderland, who at that time was responsible for antiaircaft weapons for the US Army, remained interested, and wrote that “…efforts to determine the suitability of the Bofors 40mm gun should be continued with renewed vigor,” and suggested that Ordnance officers be sent to the Swedish plant to witness a demonstration of the equipment. Captain R. R. Studler, Assistant Military Attache, London, and Major Gordon B. Welch were given the assignment and made their report after witnessing the demonstrations Aug. 18 and 20, 1937.

Based on their report, on Dec. 6 the U.S. government requested quotations from Bofors for supplying guns and ammunition. The firm replied on Dec. 22 that delivery of such material would require at least two years lead time, however, they would be willing to license production.

Chief of Ordnance Major General C. M. Wesson, was having none of this, opting instead for the U.S.-designed 37mm antiaircraft gun, and apparently persuaded Coast Artillery to change their mind, writing on Feb. 4, 1938 that, “In view of the fact the procurement of intermediate caliber weapons from foreign sources is not favorably