Italian
3"/50 (7.62 cm) Model 1909
Updated 01 August 2004
A Vickers design used as anti-torpedo boat guns on ships built before World War I.
WNIT_3-50_m1909_Duilio_pic.jpg

3"/50 (7.62 cm) guns on MM Caio Duilio
Photograph copyrighted by Giorgio Giorgerini
WNIT_12-46_m1909_Andrea_Doria_pic.jpg

Forecastle of MM Andrea Doria as viewed from the bridge about 1918
Note the 3"/50 (7.62 cm) anti-torpedo boat guns on both turrets.  In my estimation, this indicates that "B" turret, although in a "superfiring" position, could not actually fire directly over "A" turret, a limitation which was typical of British-designed mountings of the time.
Photograph copyrighted by Giorgio Ciorgerini
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Gun Characteristics
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Designation 3"/50 (7.62 cm) Model 1909
Ship Class Used On Conte di Cavour and Caio Duilio Classes
Date Of Design 1909
Date In Service 1914
Gun Weight 1.1 tons (1.2 mt)
Gun Length N/A
Bore Length 150 in (3.810 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire 10 rounds per minute
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Ammunition
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Type Fixed
Weight of Complete Round N/A
Projectile Types and Weights AP - 13.2 lbs. (6 kg)
Bursting Charge N/A
Projectile Length N/A
Propellant Charge N/A
Muzzle Velocity 2,676 fps (815 mps)
Working Pressure N/A
Approximate Barrel Life N/A
Ammunition stowage per gun N/A
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Range
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Elevation With 13.2 lbs. (6 kg) AP shell
Range @ 20 degrees 10,930 yards (10,000 m)
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Mount / Turret Data
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Designation Single Mounts
Weight  N/A
Elevation -10 / +20 degrees
Elevation Rate Manual operation, only
Train 360 degrees
Train Rate Manual operation, only
Gun recoil N/A
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Data from
"The Cavour and Duilio Class Battleships" article by Giorgio Giorgerini in "Warship Volume IV"