This is the two-seat export version of the Republic (Seversky) P-35A also known as the Seversky 2PA-L or 2PA-204A. The light bomber was offered to Sweden and 52 of ordered planes assembled in 1940 with Swedish designation B6. Because of the war embargo, there were delivered two planes only. The rest of them was taken over by the USAAF and used as training machines named AT-12 Guardsman. The bombload was of 320kg.
It might look like but the referece says just 320kg. The Polish light bomber PZL-23. Karaś carried 700 kg (1,543 lb) bombs only. But she was designed as a bomber from the beginning of the project while the P-35 was configured as a fighter machine initially. In spite of this the P-35A was able to carry 160 kg of bombs.
BTW.. the Wiki Tante says - 227kg (500lb) but also "Sweden ordered 52 2PAs (Swedish designation B6), able to carry 1,350 lb (612 kg) of bombs".