Japan
13 mm/76 (0.52") Type 93
Updated 27 May 2012
This weapon was originally designed by the French firm of Hotchkiss.  Japan imported a number of twin and quadruple mountings for evaluation purposes in the early 1930s and officially adopted the weapon on 4 February 1933.  Production of the Japanese version started in 1935.  These guns were generally similar to the larger Japanese 25 mm/60 AA MG.  The US Naval Technical Mission to Japan reported that the Japanese considered the 13 mm to be almost as reliable as the 25 mm, "since it is basically the same, but apparently not perfected to quite the same degree."

Production reached 1,200 guns per month late in 1944.  The magazine held 30 rounds and was similar in design to that for the 25 mm AA gun.

Like most nations, Japan found that small caliber MGs were inadequate against modern aircraft, but this gun was still produced in large numbers right up to the surrender.

Used a forged monobloc barrel and the automatics were gas-operated.  Actual bore diameter was 13.2 mm (0.52").
WNJAP_13mm-76_mg_pic.jpg

13.2 mm MG on Army tripod
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Gun Characteristics
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Designation 13 mm/76 (0.52") Type 93 (Model 1933)
Ship Class Used On Almost all warships of World War II
Date Of Design 1933
Date In Service about 1936
Gun Weight 92.6 lbs. (42 kg)
Gun Length oa 55.5 in. (1.410 m) [one source says 1.597 m]
Barrel Length 39.5 in (1.003 m)
Rifling Length N/A
Grooves (8) 0.006 in deep (0.15 mm)
Lands N/A
Twist
(see Note 1)		 Uniform RH 1 in 32
Chamber Volume N/A
Rate Of Fire 425 - 475 rounds per minute cyclic
250 rounds per minute practical
Notes:

1) Rifling is listed in O-47(N)-2 as being left hand twist, but I believe this to be an error, as it does not match that of any other Japanese weapon that I can find, including that of the 25 mm.

2) The barrel was secured to the breech mechanism by screw threads, but the gas cylinder connections made changeouts difficult.  Two men using a hammer and a spanner wrench could complete a changeout in about five minutes.
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Ammunition
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Type Fixed
Weight of Complete Round 4.0 - 4.2 oz (113 - 119 gms)
Projectile Types and Weights AP - 1.83oz (51.8 gms)
Incendiary Common - 1.75 oz (49.6 gms)
Incendiary Common - 1.57 oz (44.5 gms)
Tracer - 1.62 oz (46.0 gms)
Exercise - 1.83 oz (51.8 gms)
Bursting Charge Incendiary Common - 0.12 oz (3.5 gms)
AP and Exercise - None
Projectile Length 2.4 in (6.2 cm)
Complete Round 5.3-5.4 in (134-137 mm)
Propellant Charge 0.53 oz (15 gm) Type 95 (K2)
Cartridge Type and Size Brass, 13.2 x 99 mm
Muzzle Velocity 2,641 fps (805 mps)
Working Pressure 19 tons/in2 (3,000 kg/cm2)
Approximate Barrel Life 3,070 Rounds
Ammunition stowage per gun 2,500 rounds
Note:  Shell Colors

   AP - White
   Incendiary Common - Orange
   Tracer - Yellow
   Exercise - Black
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Range
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Elevation With 0.11 lbs. (0.05 kg) Shell
Range @ 45 degrees 6,560 yards (6,000 m)
Range @ 50 degrees 7,108 yards (6,500 m)
AA Ceiling @ 85 degrees Maximum:  14,764 feet (4,500 m)
Effective:  13,060 feet (3,980 m)
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Mount / Turret Data
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Designation Single, Twin and Quad Mounts
Weight  Single:  249 - 470 lbs. (113 - 213 kg)
Twin:  692 lbs. (314 kg)
Quad:  2,565 lbs. (1,163 kg)
Elevation -15 / +85 degrees 
Elevation Rate Manual elevation, only
Train 360 degrees
Train Rate Manual training, only
Gun recoil N/A
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Data from
"Naval Weapons of World War Two" by John Campbell
"World War II Fact Files:  Machine-Guns" by Peter Chamberlain and Terry Gander
"Battleships:  Axis and Neutral Battleships in World War II" by W.H. Garzke, Jr. and R.O. Dulin, Jr.
"Japanese Cruisers of the Pacific War" by Eric Lacroix and Linton Wells II
"Anatomy of the Ship:  The Heavy Cruiser Takao" by Janusz Skulksi
"Rapid Fire" by Anthony G. Williams
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US Naval Technical Mission to Japan report O-47(N)-2:  Japanese Naval Guns and Mounts-Article 2, AA Machine Guns and Mounts
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Special help from Paul Roome and Nathan Okun
Page History

09 October 2006 - Benchmark
05 December 2011 - Corrected ammunition weights
27 May 2012 - Updated to latest template