The 130 mm/50 B13 Pattern 1936 was a 130 mm (5.1 in) 50 caliber Soviet naval gun. The weapon was the standard primary armament of Soviet-built destroyers from about 1935 to 1954, and it was also utilized as a coastal gun and railway gun. The gun was produced in three different versions which all had incompatible ammunition and range tables. Mountings for the weapon included single open mounts and twin turrets. Besides the Soviet Union, the gun was used on ships sold or donated to Poland, People's Republic of China, Egypt and Indonesia. Finland captured five guns during the Continuation War and used them until the 1990s.