In previous posts, I featured two Krupp artillery pieces on display at the Armories of The Brockville Rifles. Below, Sweden's contribution to the carnage:
This is the famous 40mm Bofors L/60 anti-aircraft gun. According to Ian Hogg's book, Twentieth Century Artillery (Etobicoke, Ontario: Prospero Books, 2000), the gun was first offered in 1929 and within ten years almost every European country had bought it. The U.S. adopted the gun in 1941, and it remained in production until 1950. It was used both on field mountings as shown here, and also as a ship-board gun. The clip-loading and automatic fire were unique in a gun of this size, but it proved highly reliable and accurate in use.
Traverse and elevation controls, operated separately on each side of the gun: