Description

Not to be confused with the Oerlikon 20 mm gun used by the Allies, these German 2 cm weapons were manufactured by Rheinmetall. The Rheinmetall design was developed from an earlier Solothurn weapon, the ST-5. Both the C/30 and the C/38 guns were fully automatic.

The C/30 model was prone to jamming and used a small magazine (20 rounds) which meant frequent pauses for reloading. The later C/38 was a much improved weapon which used a 40 round magazine. A very successful variation of this weapon was the Flak 35, which combined four C/38 guns in a single quad mounting. A three-dimensional stabilized naval-mount was introduced in 1944.

The C/38 was also produced in very sophisticated twin mount for U-boats. These were able to withstand a 550 foot (200 m) diving depth.

Gun Characteristics

Designation 2 cm/65 (0.79") C/30
2 cm/65 (0.79") C/38
Ship Class Used On Almost all
Date Of Design 1930 / 1938
Date In Service 1934 / 1940
Gun Weight C/30: 141 lbs. (64 kg)
C/38: 129 lbs. (57.5 kg)
Gun Length oa 88.7 in (2.2525 m)
Bore Length 51.2 in (1.300 m)
Rifling Length 46.7 in (1.159 m)
Number Of Grooves (8) 0.0128 in deep x 0.205 in (0.325 mm x 5.2 mm)
Lands 0.104 in (2.65 mm)
Twist Uniform RH 1 in 36
Chamber Volume 2.93 in3 (0.048 dm3)
Rate Of Fire
  • C/30
    • 280 rounds per minute cyclic
    • 120 rounds per minute practical
  • C/38
    • 480 rounds per minute cyclic
    • 220 rounds per minute practical

Ammunition

Type Fixed
Weight of Complete Round 0.71 lbs. (0.320 kg)
Projectile Types and Weights HEI: 0.300 lbs. (0.134 kg)
API: 0.326 lbs. (0.148 kg)
Bursting Charge N/A
Projectile Length 3.1 in (7.85 cm)
Propellant Charge 0.265 lb. (0.120 kg) RPC/38
Cartridge: 0.41 lbs. (0.186 kg)
Muzzle Velocity HEI: 2,740 fps (835 mps)
API: 2,625 fps (800 mps)
Working Pressure 17.8 tons/in2 (2,800 kg/cm2)
Approximate Barrel Life 20,000 - 22,000 rounds
Ammunition stowage per gun 2,000 rounds 1

The sources listed below differ as to the ammunition weights, muzzle velocities, propellants and ranges. I have chosen to use those given in "German Destroyers of World War Two."

  1. ^Outfits were about 75% HEI and 25% API.

Range

Range with 0.300 lbs. (0.134 kg) HE
Elevation Distance
45 degrees 5,360 yards (4,900 m)
AA Ceiling @ 85 degrees 12,140 feet (3,700 m)

Mount / Turret Data

Designation Single Mount for C/30 and C/38: Pedestal L/30
Quad Mount for Flak 35: Vierling L/38 1
Quad 3-D stabilized Mount: Vierling C 38/43
U-boat twin mount: LM44U 2
S-boat single mount: L41
Weight L/30 with C/30 gun: 926 lbs. (420 kg)
L/30 with C/38 gun: 917 lbs. (416 kg)
Quad Mount Flak 35: 4,740 lbs. (2,150 kg)
LM44U: 7,937 lbs. (3,600 kg)
L41: 1,100 lbs. (500 kg)
Elevation 3 Single Mount: -11 / +85 degrees
Vierling: -10 / +90 degrees
LM44U: -10 / +78 degrees
L41: -10 / +85 degrees
Elevation Rate All except LM44U: Manually operated, only
LM44U: 30 or 60 degrees per second
Train 360 degrees
Train Rate All except LM44U: Manually operated, only
LM44U: 30 degrees per second
Gun recoil N/A
  1. ^In the quadruple Flak 35 mounting, distance between gun axes was 67.4 cm (26.5 inches) horizontally, 28 cm (11.0 inches) vertically.
  2. ^The LM44U had hydraulic training and elevation controlled by a joy-stick. Foot pedals operated the triggers. The mounting was bi-axial, somewhat surprising given the sophistication of the design.
  3. ^The Army Flakvierling 38 carriage had an elevation range of -10 / +110 degrees.

Additional Pictures

Sources

Data from:

  • "Naval Weapons of World War Two" by John Campbell
  • "German Warships 1815-1945" by Erich Gröner
  • "German Destroyers of World War Two (2nd Edition)" and "German Coastal Forces of World War Two" both by M.J. Whitley

Special help from Peter Lienau and Robert Hurst

Page History

05 May 2007
Benchmark
20 May 2012
Updated to latest template
12 February 2015
Added note regarding elevation range of Army quad mounting
13 March 2015
Added Flakvierling sketch