Currently, the hit sprites for Il-2/Hurri IID are the same as used for the osti when firing at the back of a panzer (orange flash and swirl of smoke). Since the osti uses HE, that would indicate that those are hitsprites for HE rounds, as they are the same regardless of range, where as (according to kvuo75) the Il-2/Hurri IID only gives an orange flash at under 600yds. You NEVER get an orange flash and a swirl of smoke when using AP rounds with a tank or M8.
The only way I could see an orange flash and swirl of smoke resulting from an AP round is if it had some HE component to it (i will admit that I don't know if the Il-2/Hurri IID does or not). But if they don't, I would like to remove the hitsprite that is consistent with HE rounds and swap it out with that used on anything of 20mm caliber and under. Seeing as it would require no new components, it seems it would be a 20-30 min project at most, since the coading for both already exists in the game.
So if there is no HE component to the rounds, the hitsprites ARE incorrect, and (IMO) should be changed.