I photographed this L60 40mm Bofors (M1?) at the Air Force Armory Museum at Eglin AFB in Florida. The Bofors gun is typically thought of in use as anti-aircraft firepower in in Single or Twin 40mm Bofors mounts. US Army also used the 40mm Bofors, and I was able to photograph an example of the M1 Bofors mounted on the M2A1 Anti-Aircraft Carriage at the Yuma Proving Grounds.
According to the Air Force Armament Museum’s social media postings, this particular example on display is the last remaining 40mm M1 gun used for AC-130 Surprise Package testing in the late 1960s