Russia
102 mm/45 (4") B-2 Pattern 1930
102 mm/45 (4") B-18 Pattern 1934
Updated 12 August 2012
The B-2 gun was a submarine wet mount modification of the 4"/60 (10.2 cm) Pattern 1911.  This design was started in 1927 and accepted into service in 1930.  The mounting was apparently unchanged from the older weapon, as the new gun was unbalanced, resulting in unequal forces needed to raise and lower the gun.  This weapon had numerous design defects including a low rate of fire and difficult loading at angles above 45 degrees.  These problems were never resolved and production stopped in 1933.  Produced at the "Bolshevik" factory with a total of 24 guns being built.

The B-18 was a twin mount intended for river gunboats.  Unlike the B-2 gun, the guns in this mounting were balanced.  A total of 7 twin mounts were installed on river monitors.

Construction of both of these guns was very similar to the 4"/60 (10.2 cm) Project 1911.  Actual bore diameter was 101.6 mm (4.0").
WNRussian_4-45_m1930_pic.jpg

102mm/45 (4") B-2 Project 1930
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Gun Characteristics
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Designation 102mm/45 (4") B-2 Pattern 1930
102mm/45 (4") B-18 Pattern 1934
Ship Class Used On B-2
Submarines:  Dekabrist (Series I), Leninets (Series II), Pravda (Series IV) classes

B-18
Dniepr river monitors:  Aktivyi, Zheleznyakov class
Date Of Design B-2:  1927
B-18:  1931
Date In Service B-2:  1931
B-18:  1934
Gun Weight B-2:  2.087 tons (2.120 mt)
B-18:  2.090 tons (2.123 mt)
Gun Length oa B-2:  179.92 in (4.570 m)
B-18:  179.69 in (4.564 m)
Bore Length Both 172.21 in (4.374 m)
Rifling Length B-2:  140.28 in (3.563 m)
B-18:  140.24 in (3.562 m)
Grooves B-2:  24
B-18:  24
Lands N/A
Twist N/A
Chamber Volume Both:  461.3 in3 (7560 cm3)
Rate Of Fire B-2:  4 - 6 rounds per minute
B-18:  6 - 12 rounds per minute
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Ammunition
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Type Fixed
Weight of Complete Round HE mod 1915 - 66 lbs. (30 kg)
FRAG mod 1915 - 66 lbs. (30 kg)
Shrapnel - 66.36 lbs. (30.1 kg)
Star Shell - 54.01 lbs. (24.5 kg)
Projectile Types and Weights HE mod 1915 - 38.58 lbs. (17.5 kg)
FRAG mod 1915 - 38.58 lbs. (17.5 kg)
Shrapnel - 39.02 lbs. (17.7 kg)
Star Shell - 33.25 lbs. (15.08 kg)
AA mod 1915 - 36.27 lbs. (16.45 kg)
Bursting Charge HE mod 1915 - 4.63 lbs. (2.1 kg)
FRAG mod 1915 - 4.15 lbs. (1.88 kg)
Shrapnel - 0.48 lbs. (0.218 kg)
Star Shell - 0.03 lbs. (0.015 kg)
AA mod 1915 - 3.09 lbs. (1.4 kg)
Projectile Length HE mod 1915 - 5 calibers
FRAG mod 1915 - 5.18 calibers
Shrapnel - 4.38 calibers
Star Shell - 4.7 calibers
AA mod 1915 - 4.75 calibers
Propellant Container Type and Weight Cartridge - 27 lbs. (12.3 kg)
Propellant Charge HE mod 1915 - 10.58 lbs. (4.8 kg)
FRAG mod 1915 - 10.58 lbs. (4.8 kg)
Shrapnel - 10.58 lbs. (4.8 kg)
Star Shell - 10.58 lbs. (4.8 kg)
AA mod 1915 - 10.58 lbs. (4.8 kg)
Muzzle Velocity HE mod 1915 - 2,477 fps (755 mps)
FRAG mod 1915 - 2,477 fps (755 mps)
Shrapnel - 2,466 fps (751.5 mps)
AA mod 1915 - 2,477 lbs. (755 mps)
Working Pressure 2480 kg/cm2
Approximate Barrel Life about 500 rounds
Ammunition stowage per gun Dekabrist - 120 rounds
Pravda - 227 total
Zheleznyakov - 150 rounds normal (250 rounds max)
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Range
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Elevation With 38.58 lbs. (17.5 kg) HE mod 1915 
Max Range 18,010 yards (16,470m)
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Mount / Turret Data
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Designation Open Single Mounts B-2
Twin Turret Mount MK-2-4
Weight  B-2:  6.4 tons (6.5 mt)
MK-2-4:  3.69 tons (37.5 mt)
Elevation Both: -5 / +60 degrees
Elevation Rate MK-2-4:  5 degrees per second
Train 360 degrees
Train Rate MK-2-4:  6 degrees per second
Gun recoil Both:  27.95 in (710 mm)
Loading Angle Any
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Data from
"Sovetskie Boevye Korabli 1941-45:  IV Vooruzhnie" (Soviet Warships 1941-45:  Volume IV Armament) by A.V. Platonov
"Entsiklopedia Otechestvennoi Artillerii" (Encyclopedia of Fatherland (Russian) Artillery) by A.V. Shirokorad
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Special help from Vladimir Yakubov
Page History

10 May 2006 - Benchmark
12 August 2012 - Updated to latest template