United States of America
0.30" (7.62 mm) Machine Guns
Updated 07 October 2007
Used in the early part of World War II on many submarines and other warships as anti-aircraft guns, but they were nearly useless in that role.  They were replaced as rapidly as possible with the 20 mm Oerlikon AA MG.

There were at least four main types used:  The Browning MG in both air-cooled and water-cooled versions using belt feed, the Lewis gun with old-fashioned magazines and the Marlin with a belt feed.  Unless otherwise noted, the data below is for the Browning MG.
WNUS_30-cal-MG_Wasp_pic.jpg

Water-cooled Browning 0.30" (7.62 mm) MG on the bridge of USS Wasp CV-7 during Guadalcanal Campaign
Detail from U.S. Naval Historical Center Photograph # 80-G-1684
WNUS_30cal_MG_aircraft_pic.jpg

Aircraft 0.30" (7.62 mm) MG
Library of Congress Photograph ID LC-USW36-86
WNUS_30cal_MG_tripod_pic.jpg

Browning 0.30 cal MG
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Gun Characteristics
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Designation 0.30" (7.62 mm) Browning Machine Gun (BMG)
0.30" (7.62 mm) Lewis Machine Gun
0.30" (7.62 mm) Marlin Machine Gun
Ship Class Used On Older submarines and many surface ships
Date Of Design about 1925 (Original Design)
Date In Service about 1930
Gun Weight N/A
Gun Length oa N/A
Bore length N/A
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate of Fire 400 - 700 rounds per minute cyclic
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Ammunition
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Type Fixed
Weight of Complete Round N/A
Projectile Types and Weights Bullet - 151 grains (9.8 gm)
Bursting Charge Solid bullet
Projectile Length N/A
Propellant Charge N/A
Muzzle Velocity 2,700 - 2,800 fps (823 - 853 mps)
Working Pressure N/A
Approximate Barrel Life N/A
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Range
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Range about 2,000 yards (1,830 m)
AA Ceiling about 4,000 feet (1,220 m)
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Mount / Turret Data
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Designation N/A
Weight N/A
Elevation about -10 / +80 degrees
Rate of Elevation Manually operated, only
Train 360 degrees
Rate of Train Manually operated, only
Gun Recoil N/A
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Data from
"Naval Weapons of World War Two" by John Campbell
"US Naval Weapons" by Norman Friedman