Twin Bofors 40mm guns

Naval anti-aircraft guns include anti-aircraft guns specially designed or adapted for mounting on ships, and naval guns adapted for high-angle fire.

Caliber (mm)	Number of barrels	Weapon name	Country of origin	Period
20	1 or 2	Oerlikon 20 mm cannon	Switzerland	World War II
20	4	Flakvierling 38 cannon	Nazi Germany	World War II
25	1, 2, or 3	Type 96 25 mm AT/AA Gun	Empire of Japan	World War II
28	4	1.1"/75 (28mm) gun	United States	World War II
37	2	3.7 cm SK C/30	Nazi Germany	World War II
40	1, 4, or 8	QF 2 pdr Mk II, Mk VIII Vickers 2-pounder "pom-pom"	United Kingdom	World War I World War II
40	1, 2, or 4	Bofors 40 mm gun	Sweden	World War II - Korean War - Cold War
45	1 or 2	45 mm anti-aircraft gun (21-K)	Soviet Union	World War II
76.2		QF 3 inch 20 cwt	United Kingdom	World War I
76.2		3"/23 caliber gun	United States	World War I - 1920s
76.2	1 or 2	3"/50 caliber gun	United States	World War I - World War II - Cold War
76.2	2	3"/70 Mark 26 gun	United States	Cold War
100	2	10 cm/65 Type 98 naval gun	Empire of Japan	World War II
102		QF 4 inch Mk V naval gun	United Kingdom	World War I World War II
102	1 or 2	QF 4 inch Mk XVI naval gun	United Kingdom	World War II - Cold War
105	2	10.5 cm SK C/33	Nazi Germany	World War II
113	1 or 2	QF 4.5 inch Mk I - V naval gun	United Kingdom	World War II - Cold War
120		QF 4.7 inch Mk VIII naval gun	United Kingdom	1920s - World War II
120	1 or 2	Type 10 120 mm AA Gun	Empire of Japan	1921 - World War II
127		5"/25 caliber gun	United States	1920s - World War II
127	2	12.7 cm/40 Type 89 naval gun	Empire of Japan	1932 - World War II
127	1 or 2	5"/38 caliber gun	United States	1934 - World War II - Cold War
127		5"/54 caliber Mark 16 gun	United States	Cold War - Korean War
127		5"/54 caliber Mark 42 gun	United States	Cold War - Korean War - Vietnam War
133	2	QF 5.25 inch Mark I naval gun	United Kingdom	World War II
152	2	6"/47 caliber Mark 16 gun	United States	Cold War - Korean War
152	2	QF 6-inch Mark N5 gun	United Kingdom	Cold War