Hello. I realized the BR-412D in use on soviet MBT T54 family (1947, 1949, 1951) is different.
All of the three versions have the same ammunition type available to use, with the same characteristics (ofc) but the 1947 version has the thumbnail with a thicker armour layer compared to the 1951 and 1947 tank thumbnails.
Also, BR-412D in-game descriptions considers this ammunition as APCBC round with HE filled cap in it. According to wt wiki, APCBC rounds does not have any he filler, but the APHEBC/CBC has.
For instance, the BR-412/B both have HE filler and the description matches with them.
Not sure if I explained everything fine, feel free to correct me.
have a nice day and thanks