Adjusting the hardness for [BAT] seemed to affect only the two strange box trucks. I upped my lethality against armor from 1.0 to 10.0 and still no change. If I hit jeep, 251, M4, T-34, Tiger, I see an explosion but no permanent destruction. Doesn't matter where I hit it either. Same explosion, no ricochet rounds.
Haven't yet got through every single hardness setting. I wish there was a key for the different abbreviations.