A Bofors design, these were used on Sweden's Pansarskepp (Armored Ships) that were active between 1917 and 1947. They were then kept in the reserve fleet until the late 1950s. These guns were of built-up construction with a hand-operated screw breech-block of the Bofors ogival type. They had a high rate of fire and were considered to be quite accurate.

In the 1930s a more aerodynamic "Arrow Nose Shell" was developed which gave an increased range.

One of the guns from Drottning Victoria is now a museum piece at the Karlskrona Naval Base.

Gun Characteristics

Designation 28.3 cm/45 (11.1") Model 1912
Ship Class Used On Sverige Class
Date Of Design 1912
Date In Service 1917
Gun Weight 43.4 tons (44.1 mt)
Gun Length oa 501.4 in (12.735 m)
Bore Length about 484.1 in (12.295 m)
Rifling Length 414.0 in (10.515 m)
Grooves 80
Lands N/A
Twist Increasing RH 1 in 50 to 1 in 28
Chamber Volume N/A
Rate Of Fire 3 - 4 rounds per minute


Type Bag
Projectile Types and Weights AP: 672.4 lbs. (305 kg)
Bursting Charge N/A
Projectile Length N/A
Propellant Charge 220.5 lbs. (100 kg)
Muzzle Velocity 2,854 fps (870 mps)
Working Pressure 19 tons/in2 (3,000 kg/cm2)
Approximate Barrel Life N/A
Ammunition stowage per gun N/A


Range with 672.4 lbs. (305 kg) AP
Elevation Distance
18 degrees 21,435 yards (19,600 m)
Range with 672.4 lbs. (305 kg) Arrow Nose
Elevation Distance
20 degrees 26,250 yards (24,000 m)
25 degrees 31,700 yards (29,000 m)

Armor Penetration

Armor Penetration with 672.4 lbs. (305 kg) AP
Range Vertical KC Armor Horizontal Armor
6,560 yards (6,000 m) 350 mm ---
19,690 yards (18,000 m) 155 mm 87 mm

Data from Bofors proof testing as detailed in "Från monitorer till pansarskepp."

Mount/Turret Data

Designation Two-gun Turrets: Sverige (2)
Weight 348.1 tons (353.7 mt)
One sources says 406 tons (413 mt)
Elevation As built: -5 / +18 degrees 1
Elevation Rate 5 degrees per second
Train about +150 / -150 degrees
Train Rate 4 degrees per second
Gun recoil 28.7 in (73 cm)
Loading Angle 0 degrees

Gun axes were about 83 in (210 cm) apart.

  • ^"Naval Weapons of World War Two" says that some reports state that the elevation was increased to 35 degrees. However, Joakim Wohlfeil informs me that the maximum elevation for these guns never exceeded 25 degrees. "Från monitorer till pansarskepp" says that increases were contemplated but never carried out due to financial restrictions and that the elevation may never have exceeded 19 or 20 degrees.

Additional Pictures

All pictures are of Pansarskepp Sverige and are courtesy of Joakim Wohlfeil.


Data from:

  • "Naval Weapons of World War Two" by John Campbell
  • "Från monitorer till pansarskepp" by Per Insulander and Curt S. Ohlsson

Special help from Stefan Bengtsson, Jeff Brantly, Hans Lineskär and Joakim Wohlfeil

Page History

06 October 2007
07 February 2016
Added note about museum gun