12 cm Mark 4, 5, 6 and 7

The Mark 4 was built in the Boforsfactories in Sweden, the Mark 5, 6 and 7 were built under license by Wilton Feijenoord in Schiedam, Holland. The difference was the mounts used.

Rear turret of Willem van der Zaan

Gun specs
Manufacturer Bofors, Sweden
Gun type Bofors 4.7 inch Mark 4, 5, 6 and 7.
Purpose Low angle (seatargets only)
Bore 120 mm (4.7 inch)
Classes used on Mark 4: 1st batch Admiralen-class destroyers
Mark 5: 2nd batch Admiralen-class destroyers
Mark 6: Van Kinsbergen-class sloop
Mark 7: Van der Zaan-class minelayer
Date of design 1924
Date in service 1926 (commissioning first Admiralen-class destroyer)
Length 50 calibers (6,39 m)
Gunweight 4 tons
Initial velocity 2950 feet/sec
Rate of fire 10 rounds/minute
Shell specs
Shell types HE shells
Shell weight 53 lbs
Range (max) 19.500 m @ 35 degrees
Mount specs
Mount types Mark 4/5 Non- or half shielded open mounts
Mark 6: Armoured turret
Mark 7: Armored shields
Mount armor  
Elevation Mark 4: -5/ +30 degrees
Mark 5 / 7: -5 / +35 degrees
Mark 6: -5 / +45 degrees
Train - 150 / + 150 degrees
Train method manually

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