High Explosive Bonus is an attribute that unlocks once the honor level reaches 11.

The high explosives will be loaded on tanks at level 8 or higher, which increases shock damage.
To check whether this attribute is activated for a specific tank type, follow these steps:

-Click on the wanted tanks factory
-Click on "Train"
-Slide the screen and choose the required unit
-Click on the unit's name.
-Look for the "Ammo" Tab and click on it to view more details.

Note: If you can't find the Ammo tab, it means the attribute is not activated for that type of tanks.

-The higher your Honor ranking, the higher this attribute will become.