French
138.6 mm/40 (5.46") Model 1927
Updated 22 July 2007
The unsatisfactory performance of the 138.6 mm (5.46") Model 1923 resulted in a new design based upon a gun from a former enemy.

The Model 1927 was developed from the German 15 cm (5.9") gun used on the destroyer S113, which was taken over by France at the end of World War I and renamed Amiral Sénès.  Like the German weapon, the Model 1927 was fitted with a horizontal sliding wedge breech-block of semi-automatic operation.

The barrel was autofretted and used the same shells and cartridge cases as in the 138.6 mm Model 1929, but with a smaller propellant charge.
WNFR_55-40_m1927_Pluton_pic.jpg

NMN Pluton
WNFR_55-40_m1927_Cassard_pic.jpg

"2400 Tonnes" Destroyer Cassard in 1933
Ministère de la Défense Photograph
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Gun Characteristics
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Designation 138.6 mm/40 (5.46") Model 1927
Ship Class Used On Pluton, Aigle, Cassard and Le Malin classes
Date Of Design 1927
Date In Service 1930
Gun Weight N/A
Gun Length oa N/A
Bore Length about 218.3 in (5.544 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire 8 - 10 rounds per minute
Note:  The gun itself could fire about 12 or 15 rounds per minute.  However, the dredger hoists could not keep up with this speed, resulting in the lower figure listed above.
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Ammunition
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Type Separate
Projectile Types and Weights SAP - 89.5 lbs. (40.6 kg)
HE - N/A
Bursting Charge N/A
Projectile Length SAP - 26.9 in (68.3 cm)
Propellant Charge 19.8 lbs. (8.97 kg) BM7
Cartridge - 48.5 lbs. (22 kg)
Muzzle Velocity 2,297 fps (700 mps)
Working Pressure 15.9 tons/in2 (2,500 kg/cm2)
Approximate Barrel Life N/A
Ammunition stowage per gun N/A
Note:  The same size cartridge case was used in all 138.6 mm (5.46") guns from the Model 1910 onwards, although the type and quantity of propellant was not always the same.  This allowed obvious advantages in terms of standardization, although much of this was lost by the fact that almost every model used different projectiles.
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Range
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Elevation With 89 lbs. (40.4 kg) SAP Shell
Range @ 28 degrees 18,150 yards (16,600 m)
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Mount / Turret Data
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Designation Single Mountings
   Pluton (4), Aigle (4), Cassard (4) and Le Malin (4):  Model 1927 CP
Weight  12.8 tons (13 mt)
Elevation -5 / +28 degrees
Elevation Rate N/A
Train about +150 / -150 degrees
Train Rate N/A
Gun recoil 14 in (36 cm)
Loading Angle Any
Note:  Used an automatic spring rammer.
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Data from
"Naval Weapons of World War Two" by John Campbell
"Destroyers of World War Two" by M.J. Whitley
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Ministère de la défense