The first of the famous Bofors automatic guns, this version was the first one ordered by the Swedish military and was designed for submarine use. The gun and mounting was designed to be lowered into a water-proof tubular compartment under the decking. This was accomplished by elevating the gun to 90 degrees and then folding the fire-control handles and spent-cartridge chute up against the gun.
This weapon was very similar in design to the later Bofors 40 mm/60 gun and used the same ammunition as that did that gun but with a reduced propellant load.
Non-folding single and twin mounts were produced and exported to Poland, but the Royal Swedish Navy used only the single folding mount.
The last Swedish submarine with this gun was decommissioned in 1966.
|Designation||40 mm ubätsautomatkanon M/32|
|Ship Class Used On||Sjölejonet and Neptun classes
Exported to Poland
|Date Of Design||1930|
|Date In Service||1932|
|Gun Weight||243 lbs. (110 kg)|
|Gun Length||about 67.7 in (1.72 m)|
|Twist||Increasing RH twist|
|Rate Of Fire||120 to 140 rounds per minute cyclic
80 to 90 rounds per minute practical
|Projectile Types and Weights||AB 40 mm L/60 HE-T: 2.05 lbs. (0.93 kg) 1|
|Weight of Complete Round||about 4.41 lbs. (2.0 kg)|
|Bursting Charge||HE-T: about 0.150 lbs. (0.068 kg) TNT|
|Projectile Length||7.25 in (18.4 cm)|
|Complete Round Length||17.60 in (44.7 cm)|
|Cartridge Case Type, Size and Empty Weight||Brass, 40 x 311R, 1.93 lbs. (0.88 kg)|
|Propellant Charge||0.485 lbs. (0.220 kg)|
|Muzzle Velocity||2,297 fps (700 mps)|
|Approximate Barrel Life||N/A|
|Ammunition stowage per gun||N/A|
- ^As noted above, this was the same ammunition as produced for the Bofors 40 mm/60 but with a reduced propellant charge. Rounds were self-destructing.
|Max Horizontal Range
|about 4,800 yards (4,370 m)|
|Max Possible Horizontal Range
|about 10,900 yards (9,980 m)|
|Max Vertical Range
|about 14,650 feet (4,460 m)|
- "The Bofors Gun" by Terry J. Gander
- 30 December 2015
- New datapage