Built by Bofors, these guns were mounted on Coastal Defense vessels.

Constructed of A tube, two part jacket and screwed-on breech piece. Originally used a sliding horizontal breech mechanism but was later fitted with a conventional Welin breech mechanism.

Gun Characteristics

Designation 254 mm/45 (10") Bofors
Ship Class Used On Väinämöinen class
Date Of Design about 1929
Date In Service 1932
Gun Weight 37.3 tons (37.9 mt) including breech mechanism
Gun Length oa 262.6 in (10.339 m)
Bore Length about 450 in (17.717 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire about 2 - 3 rounds per minute


Type Separate
Projectile Types and Weights APC: 496 lbs. (225 kg)
Bursting Charge N/A
Projectile Length N/A
Cartridge Case Type, Size and Empty Weight probably brass, size N/A, 99 lbs. (45 kg)
Propellant Charge 154 lbs. (70 kg)
Muzzle Velocity 2,789 fps (850 mps)
Working Pressure N/A
Approximate Barrel Life N/A
Ammunition stowage per gun N/A


Range with 496 lbs. (225 kg) AP Shell
Elevation Distance
45 degrees 33,140 yards (30,300 m)

Mount/Turret Data

Designation Twin Mounts: Väinämöinen (2)
Weight 252 tons (256 mt)
Elevation -10 / +45 degrees
Elevation Rate N/A
Train about +150 / -150 degrees
Train Rate N/A
Gun recoil 26.6 in (67.5 cm)
Loading Angle 0 degrees

The turret was on a ball track and was electrically powered with hydraulic drive for training and elevation. Guns were individually sleeved but could be coupled together.

Additional Pictures


Data from:

  • "Naval Weapons of World War Two" by John Campbell