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").
|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)|
|Grooves||(8) 0.006 in deep (0.15 mm)|
|Twist||Uniform RH 1 in 32 1|
|Rate Of Fire||425 - 475 rounds per minute cyclic
250 rounds per minute practical
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.
|Weight of Complete Round||4.0 - 4.2 oz (113 - 119 gms)|
|Projectile Types and Weights 1||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|
Shell Colors AP White Incendiary Common Orange Tracer Yellow Exercise Black
|45 degrees||6,560 yards (6,000 m)|
|50 degrees||7,108 yards (6,500 m)|
|AA Ceiling @ 85 degrees||Maximum: 14,750 feet (4,500 m)|
|Range against aircraft||Maximum: 6,550 ft (2,000 m)
Effective: 3,300 ft (1,000 m)
"Naval Weapons of World War Two" states that the effective range of this weapon was 13,060 feet (3,980 m), but this seems much too long compared to similar weapons such as the USA 0.50" (12.7 mm) and British 0.50" (12.7 mm) machine guns. "US Naval Technical Mission to Japan report O-47(N)-2" has the same maximum ranges as does "Naval Weapons of World War Two" but states that the effective range was 1,650 yards (1,500 m) which seems more reasonable. The above "Range against aircraft" values are from "Japanese Cruisers of the Pacific War" and I consider these to be likely for a manually aimed weapon of this caliber.
- "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
- US Naval Technical Mission to Japan report O-47(N)-2: Japanese Naval Guns and Mounts-Article 2, AA Machine Guns and Mounts
Special help from Paul Roome and Nathan Okun