U.S.S. Allen M. Sumner DD-692
Machine Gun Batteries

The history and images we have of the Machine Gun Batteries is limited and we invite your participation in telling this story.

40-mm Mk 1 and Mk 2 Guns
40-mm Twin Mk 1 and Quadruple Mk 2 Mounts

The 40-mm heavy machine gun was developed as the Bofors 40-mm by a German Krupp design in 1918. It was redesigned for mass production by the Navy in single, twin and quadruple versions. The Mk1 and Mk2 differed only in the arrangement of the hand controls for right or left use. The gun was feed by magazine clips of 4 rounds each weighing approximately 4.5 lb. They could be fired in single or automatic fire at a rate of 160 rounds per minute. The few photos we have are all of the guns as they appeared on the Sumner. The after torpedo mount (Mk 15) was removed in 1945 and replaced with a quadruple Mk 2 mount. All of the 40-mm mounts were removed during the overhaul in Boston in 1952.

40-mm guns as originally installed 40-mm guns as they appeared before the 3"/50 installation
Single gun version of the 40-mm Mount

20-mm Mk 2 and Mk 4 Guns
20-mm Single Mk 4 and Mk 10 and Twin Mk 24 Mounts

The 20-mm gun was derived from the Swiss Oerlikon and mounted aboard in single and twin mounts. The 20-mm had no external power and was hand aimed using automatic fire. The shells weighed just over one-quarter pound fed through magazines containing 60 or 100 rounds. Firing rate was 450 rounds per minute, however, this could not be achieved because of the magazine capacity. These guns were mounted throughout the ship in just about any available location. The 20-mm mounts were removed shortly after the end of World War II.

3 inch/50 caliber Mk 22 Guns
3 inch/50 caliber Twin Mk 27 and Mk 33 Mounts

With the increase in the size and speed of aircraft and the introduction of jet aircraft the 20-mm and 40-mm guns were considered obsolete and during the 1952 overhaul they were replaced by the 3"/50 guns. While they may not be considered true machine guns they were the replacement for the World War II era machine gun battery. They were placed aft where the Mk 15 Torpedo Mount and the Quad 40-mm had been located. The Mk 22 was semiautomatic and power driven firing fixed AAC or HC rounds. Using the Mk 31 and Mk 33 projectile  along with the Mk 7 and Mk9 cartridges and VT fuzzes the projectile averaged about 13 pounds and the cartridge containing about 11 pounds of powder with a total round weight of 34 pounds. Firing rate was 50 rounds per minute. These guns were removed during the FRAM II overhaul in 1961 and replaced with the DASH QH-50c system.

Other Small Machine Guns

Other small machine guns were also used over Sumner's life including the Thompson .45 ACP Machine Gun and the standard .50 Caliber M2 "Ma Deuce" Machine Gun. The photos below show the Thompson being tested during the Korean Deployment in 1953 and the M2 during the Vietnam Deployment. The M2 had been placed aboard when the ship reached Yokosuka, Japan in March 1967 and was removed again as the ship headed home in Yokosuka in August 1967.

The Thompson
The Ma Deuce
BAR's, Shotguns, Thompson Sub Machine Gun and .30 caliber Machine Gun

Shipmate Memories

From Vins Holbrook (SM2c 43-45): The Thompson was used during the Mindoro invasions during the Philippine Campaign as a result of a CINCPAC memo (I think) warning us that there was a real threat from enemy swimmers hiding under boxes or cans and attempting to attach explosive devices to our ships.  Whether this was a "rumor" or not I don't know, we never actually witnessed such an occurrence.  Anyway, I recall the OD and/or other officers on the bridge expending several magazines into oil drums, orange crates and other assorted debris on several occasions.  None of these objects ever exploded but it was a chance to shoot a Thompson Sub-Machine Gun and I don't think anyone would pass on it if they got the chance.

Many thanks to Harold Jackson, Jim Walker, Al Payne, Richard Sementelli, Doug Rinear, Hank Lunki and Lew Grasso for sharing their photographs with us.