A 40 mm Bofors cannon M1936, modernised in the early 1960s. Forty-three Bofors cannons were modernised by equipping them with the Italian Galileo P36 calculator and aiming system.

The setpoints in the on-gun calculator are target speed and the slope distance to the changeover point. (The changeover point is the intersection of the target flight path and a straight line from the cannon to the flight path, i.e. the shortest distance from the cannon to the target flight path.)

The aiming system includes:

• a 6hp Lambretta two-stroke engine
• a generator charging the battery
• hydraulic pumps and motor
• gun-laying equipment
• on-gun calculator
• sights

SPECIFICATIONS:

• calibre 40 mm
• muzzle velocity 800 m/s
• effective range 3000 m
• rate of fire 120 rounds per minute
• weight 2650 kg

References: Vehviläinen Raimo et al., Itsenäisen Suomen Ilmatorjuntatykit 1917–2000, Sotamuseo, Helsinki 2005; Palmu Pentti, Yön yli päivään – Suomen ilmatorjunnan vaiheita 1925–1990, Ilmatorjuntaupseeriyhdistys Ry, Helsinki 1989; Ilmatorjuntajoukot 1925–1960, Ilmatorjuntaupseeriyhdistys Ry, Helsinki 1963