After World War II, many shell stocks for the German 12.8 cm naval gun remained in Poland. In the 1960s, the country decided to begin a project for the Krazownik* heavy tank with armament designed to use this ammo. The Soviet B-13 naval gun was considered as an alternative. The estimated cost of the project rose significantly during development, and, as the ammunition was quickly becoming outdated, the project was terminated at the blueprint phase.