Lighting it up
Here we see a U.S. Army Anti-aircraft gun battery at, Fort Shafter, Hawaii in 1925 practicing with their then-standard 3-inch M1918 guns (76.2 mm L/40), which was actually based on the old M898 3″/23 caliber gun. These in turn were replaced by the 90mm M1 in the early 1940s. There are only a handful of the old M1918s left as museum pieces.
And here we see the British counterpart in the form of a battery of Vickers QF 3.7-inch AA guns in action near Tobruk during a night raid in 1940. Though largely withdrawn from British and Commonwealth use by the early 1960s, there are apparently a few QF 3.7’s still in use on the roof of the world in Nepal.