According to the shooting writer known as BB Pelletier, BSF failed because of their poor distribution network. I can believe that because BSF rifles seem to have been rarely encountered in gunshops in the 70s/80s when compared to the widespread HW and FWB. The British importer, Norman May, also went bust IIRC and that restricted BSF's access to the crucial British market. A pity as the gun's were very good. Weihrauch took over the BSF operation and according to BB Pelletier this had a positive influence on HW's designs. So BSF still lives on in a way...