investigating 9M120 Ataka explosive weight

[AeriaGloria]

Hello, 9M120 tandem HEAT explosive weight in game is currently 7.4 kg which is weight of the whole warhead. This makes sense for thermobaric 9M120F version where whole  warhead might be filled and is often quoted as having an explosive amount effective to 9.5 kg of TNT,  however for tandem HEAT it could not be same weight as entire warhead especially with the empty space taken up by the telescoping probe. 
 

According to this site, which lists many sources but not one specific for this figure, lists 2.75 kg for the explosive charge. As it is the Ataka has almost twice the power of the 4 kg Vikhr warhead. https://thesovietarmourblog.blogspot.com/2021/07/soviet-atgms.html?m=1
 

I can find no other sources, while I know certain warheads use the the entire warhead weight as explosive to make up for fragmentation, im not sure that is the intention here. Thank you