The Polish developed 7,92x107 mm anti tank cartridge used a 245 gr lead steel jacket bullet fired at 4,180 FPS (barrel life about 300 rounds). The Polish designed bolt action rifle KB wz 35 fired this cartridge, rifle weight was 22 lbs. This cartridge was able to penetrate the Panzer I, Panzer II and Panzer III.
Photo shows 7,92 Kurz and dummy 7,92x107mmAttachment 102013