The origins of this weapon go back to 1929, when the design of a 130 mm/45 (5.1") submarine "wet-mount" gun was started. This weapon was to have high barrel pressure in order to match the performance of the 130 mm/55 (5.1") Pattern 1913 gun. However, this design turned out to be too big for the "Pravda" class submarines. For that reason, the design was modified to allow it to be used on destroyers. Changes included lengthening the barrel to 50 calibers and lowering the barrel pressure. Wet mount features, such as using fixed ammunition, were also dropped in order to reduce the cost of this weapon. After many delays, the weapon was tested and accepted into service in 1936. Curiously, serial production actually started in May 1935. This might have been due to the fact that the Destroyer Leader Leningrad was launched in 1933 but had remained incomplete awaiting delivery of these guns.

The desire to keep the same ballistics as the 13 cm/55 (5.1") gun led to an increased barrel pressure, which in turn led to a very short barrel life of only 130 rounds. This meant that Pr. 1 Leaders and Pr. 7/7U Destroyers couldn't even empty their magazines a single time before needing to change out the barrel. After many design changes (including trying to manufacture a polygonal gun barrel), the remedy was found to be making a liner with deeper grooves. The original liner had 1.0 mm (0.039") deep grooves, while the new liner had 2.7 mm (0.106") deep grooves. In the end the fleet was equipped with what amounted to be three different guns, a design with 1.0 mm (0.039") grooves, a design with 1.95 mm (0.077") grooves and a design with 2.7 mm (0.106") grooves. Unfortunately, this meant that the guns, ammunition and range tables were all incompatible with each other, which greatly complicated the logistics for these weapons. By 1941 there were 378 guns in service, most of which were of the deepest groove type.

These weapons were widely used in World War II and remained in production until 1954 with a grand total of 1,199 guns being manufactured.

Prior to the start of World War II a development of the DP version of the B-2 turret was started. This turret was designated as B-2-U (U meaning Universal'naya - Universal). It was to use a barrel extended to 55 calibers. These turrets were intended to be used on the next generation of destroyers and destroyer leaders, but the war stopped the project and none were built.

Overall this was a good destroyer gun in its later incarnations. However, it was only slightly lighter than the older 13 cm/55 (5.1") Pattern 1913 and had a breech mechanism that never seemed to work properly.

Early guns were monobloc but later guns changed to a loose liner.

• ^The B-13 mount had sharp corners while the B-13-2 mount had rounded corners. Both variations were often used on the same ship, apparently depending upon what was available during construction. These were open-back shielded mounts. Lower mountings were protected from upper mount blast by having an extended roof.

130 mm/50 B13 at Moscow Victory Park - Pictures by Vladimir Yakubov

"Naval Weapons of World War Two" by John Campbell
"Soviet Destroyers of World War II" by Alexander Hill
"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
"Destroyers of World War Two" and "Cruisers of World War Two" both by M.J. Whitley
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Special help from Vladimir Yakubov

11 September 2006 - Benchmark
29 May 2018 - Converted to HTML 5, reorganized notes, added information on differences between B-13 and B-13-2 mountings