Originally developed as a small anti-torpedo boat gun. During World War I this weapon was mounted on some landing craft and also used as a landing gun. Used during World War II on some small coastal defense boats and submarine chasers.

Gun Characteristics

Designation 6 cm/21 (2.4") Casemate Gun C/98
6 cm/21 (2.4") S-Bts KL/21
6 cm/21 (2.4") Bts KL/21
Ship Class Used On Boat Gun
Date Of Design 1898
Date In Service 1900 (?)
Gun Weight N/A
Gun Length oa 107 in (0.121 m)
Bore Length 99 in (2.505 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire 12 - 14 rounds per minute


Type Separate
Projectiles and Weight HE: 6.0 lbs. (2.71 kg)
Shrapnel: 5.2 lbs. (2.38 kg)
Bursting Charge HE: 0.32 lbs. (0.144 kg)
Projectile Length HE: 7.5 in (19 cm)
Propellant Charge 0.25 lbs. (0.115 kg) W.P. 07
Cartridge 1.74 lbs. (0.79 kg)
60 mm x 64 mm R
Muzzle Velocity HE: 1,434 fps (437 mps)
Shrapnel: 1,470 fps (448 mps)
Working Pressure N/A
Approximate Barrel Life N/A
Ammunition stowage per gun N/A


Range with 6.0 lbs. (2.71 kg) HE
Elevation Distance
Range Maximum 3,720 yards (3,400 m)

Mount / Turret Data

Designation Single mounts
Weight N/A
Elevation N/A
Elevation Rate Hand operated, only
Train N/A
Train Rate Hand operated, only
Gun recoil N/A

Additional Pictures


Data from:

  • "Naval Weapons of World War Two" by John Campbell
  • "Munitionslexikon Band2" by Karl R. Pawlas
  • "Waffenlehre" by Richard Berlin Wille

Special help from H. Zertner and Peter Lienau

Page History

28 May 2008
19 May 2012
Updated to latest template
22 April 2016
Added photographs of gun from early 1900s