The U.S. SUBMARINE WAR
  in the PACIFIC  1941 - 1945


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3 Inch 50 Caliber MK21 Deck Gun Cannon
WWII U.S. Submarine Weapons and Armament 1941 - 1945


 
 
 

 

 

 

The 3 inch 50 caliber Mk 21 (76mm) dual purpose cannon deck gun was standard issue on board many United States Navy Submarines, Destroyers and Destroyer Escorts (DE) during the early stages of World War II. By US Navy standards, it was generally considered to be a defensive weapon designed to be used against aircraft that were far away or very high up, although on a submarine it was primarily employed against enemy surface ships. Mounted on a pedestal either forward or aft of the conning tower, this weapon could fire a 13 lb high explosive projectile with a muzzle velocity of 2,700 feet per second and a maximum range of just over 16,000 yards with a ceiling of 21,500 feet. This gun could elevate to 85 and depress to 10. Cartridges were packed four to a box, the weight of a full box being about 125 lbs with cartridges weighing approximately 32lbs each. The 3 inch 50 had a watertight tampion for the muzzle and a watertight cover for the breech with stainless steel mechanisms and bore. This weapon could be used with equally deadly effect against both surface and aerial targets.

 
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  RESOURCE NOTES:
Product photo
United States Submarine Operations in World War II
By Theodore Roscoe
United States Naval Institute
George Banta Company Inc Copyright 1949
Product photo Silent Victory: The U.S. Submarine War Against Japan
By Clay Blair
J.B. Lippincott Company
Copyright 1975
Product photo Subs Against the Rising Sun:
U.S. Submarines in the Pacific

By Keith H. Milton
Yucca Free Press
Copyright 2000
Book Cover U. S. Submarines in World War II:
An Illustrated History of the Pacific

By Larry Kimmett & Margaret Regis
Navigator Publishing
Copyright 191996
 
   

 


 
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