I don't claim to be an expert in WoT damage physics, but with all the discussion on HE since the 7.0 patch, I was curious to try some actual controlled experiments and quantify damage. Specifically I wanted to quantify the average damage to a KV (it used to be about 15-20% before the patch), see if I could bounce a shot off the ground below the KV and cause splash damage (and find out how much), see if I could cause more damage by hitting the spot where the turret rubs against the hull (splash damage hitting allegedly weaker top surface of the hull), and see if splash damage to the top of the hull at the rear of the tank (engine deck) would cause more damage than hitting the hull directly.
To do this, Montykoro and I conducted an empirical experiment in which 48 105-mm SPH M4L23 rounds were fired at close range (10-14 m) by an elite M4 Sherman at an elite KV (no spall liner on the KV). 10 different aiming locations were explored to understand the damage effects of the M4's HE shell explosions.
Many thanks to Montykoro, who patiently sat in in KV taking round after round and reporting critical hits.
I present the initial conclusions first, with all the gory details below. I say "initial" because I don't claim to be the definitive expert on this, and I'm sure the results will benefit from future discussions and constructive comments posted below and in other threads. Please feel free to add your constructive comments, ideas, and questions below. And please give Montykoro a +1 if you see him since he's such a great test subject (his KV crew needs vodka too after enduring 48 HE rounds over the course of several tedious training game sessions). So...
General Conclusions Regarding HE
Additional Conclusions Specific to M4 Sherman Drivers that Use the 105 mm Against a KV
The Details (SCIENCE!)
Results and Discussion