It always bothered me that French Hispano-Suiza 404 Cannons use the same ammunition as the British Hispano 20mm cannons. The same ammunition is also found on the Swedish Fokker with twin Oerlikon FF cannons.
Does anyone have any information about the historical development of Hispano and Oerlikon ammunition?
I know that Britain only used Ball and maybe explosive rounds at the early stages of the war and later developed AP and SAP-I rounds.
Same with early British (and German) planes, French planes therefore shouldn’t have access to later developed ammunition types like SAP-I.
I would also assume that early explosive rounds were just HE instead of HEI, since most nations later added incendiary compounds to the shell or gave the explosive incendiary properties.
Japan also used the Oerlikon FF in form of the Type 99-1 cannon, which as far as I know came with foreign Ball, AP and HE ammunition as well as domestic developed rounds.