Unfortunately, that is a test that's highly susceptible to human error and skill influencing the outcome. Namely, I don't think you know where to shoot the T-34.
I ran the same test, and my results for the Panzer 4 shooting the T-34:
1-hit kills: 19
2-hit kills: 18
3-hit kills: 10
4-hit kills: 3
5-hit kills: 0
Total hits: 97
Average hits: 1.9 (1.94 if we go to three significant digits)
I was careful to follow the same conditions that you posted. Despite that, there were three times I decided to engage a T-34 when it was angled at 30 degrees. All three were shot in the hull front, and all three resulted in a one-hit kill.
However, I am a little unclear on one thing you said. When you say bounces weren't counted, do you mean you didn't count any shot that did not penetrate as a hit? I wasn't sure, so I included those in my numbers, though they were fairly few. If they shouldn't be counted, my total hits would be about 5-10 or so less (If we go with 5, about 1.84 penetrations per kill).
Did some more testing in more variable conditions; shooting at a T-34 from even a very slight angle above horizontal makes 1-shot kills extremely common. This also includes long-range shots, where the round is coming down at a steeper angle. Firing from an angle below that of the T-34 makes it harder, unless you have a clear line on the lower-front hull; generally took me only 1-2 hits if I could, 3-4 if not. So long as you shoot at a plate that's fairly flat to you, you can penetrate it, and I never saw a T-34 at enough of an angle to bounce off the front glacis while still able to depress the gun to me.
T-34/76
TOTAL HITS: 125
AVERAGE: 2,5 HITS PER KILL
1 HIT KILLS: 13 (26%)
2 HIT KILLS: 10 (20%)
3 HIT KILLS: 17 (34%)
4 HIT KILLS: 08 (16%)
5 HIT KILLS: 02 (04%)
I count 126 hits, there.
PANZER IV/G
TOTAL HITS: 94
AVERAGE: 1,8 HITS PER KILL
Rounding does not work that way. If you're reducing it to two significant digits, that would be 1.9. Three significant digits would be 1.88.
Sometimes bot tanks are really getting blown up by machine gun fire, some times in a row, some nearby tanks get destroyed like this. I found this out, because to draw enemy tanks to face my head on, firstly I used machine gun fire from the paraxial mg on them, and a very few blew up.
That's a real strange one, yeah. I have to wonder if that's a single-player only bug, or if it affects multi-player at all. It's possible that it has something to do with the implementation of hit-registration, if it's somehow applying the MG hits directly to HP. If it were giving penetration flashes, I'd almost think that sometimes the MG is firing bullets coded as tank-cannon rounds.
Incidentally, it's a "coaxial" or "coax" MG.
When the T-34's hull is looking well up, in an angle that favors it's glacis, that plate becomes literally immune to fire from the Panzer. I just don't think the T-34 it self can shoot its enemies at that point, but still a good defense mechanism.
On the plus side, that usually presents the lower-front plate at a much flatter angle, making it a valid target, and you're almost assured to hit the big main ammo store.
How much energy remains from an AP round, from how much it looses depending on the armor it goes through, seems to have an effect on it's probability of taking out a weakspot.
Urgh... Well, that got me to actually dig through the tank code. I'd advise people against it. It's a mess (Hell, even the indentation is inconsistent!). However, on a quick skim, there seems to be no way for vehicle armor penetration to alter the ImpactDamage of a anti-vehicle round. I can't swear it's so, but it appears to be that way. I'm not bothering to dig further to figure it out. This code makes me angry.
However, my digging did turn up some interesting things. It looks to be impossible to deal more than 5 penetrations to a vehicle without killing it. To do so, you have to have missed all internal damageable zones. The tanks have 800 health, while the projectiles have ImpactDamage 400. If you hit no interior zones, it deals only 0.375 times ImpactDamage. Otherwise it does full. On top of that, there is a DamageMultiplier that is commented to multiply all damage to that zone by that amount, and a KillPercentage that is commented as a chance to instantly kill the vehicle (0.2 or 0.3 for most vulnerable areas). It appears that KillPercentage actually works as a chance to apply that DamageMultiplier (Though it's functionally an instant-kill in that case, as even the lowest DamageMultiplier, for fuel, is 10. More than enough to kill the tank). This also means that two penetrations hitting any interior zone
should always kill the tank. I don't know how it handles penetrating multiple zones, that might actually deal reduced damage, but I got tired of the code by then and didn't dig through that, too.
Also, it seems spalling can only hit crew.
explaining why targeting the same weakspot from the side is many times more effective than from the front. Either that, or the fact that from the side the same shot probably hits multiple weakspots, raising it's own chance naturally.
Very much the latter.A somewhat straight-on side shot on the T-34 can pass through as many as 4 vital areas (Two fuel, two ammo). Okay, theoretically 5, but the vector you'd need for that is incredibly small. From the front you're very unlikely to get more than 2.
Which is in anyway, in my opinion, a poor system. Since, I believe, a huge weakspot will give out the same probability as a weaker one.
In general, the big ammo stores have KillPercentage 0.3, while the small ones have 0.2. The hull MG ammo store in the T-34 has KillPercentage 0 (Which appears to mean no chance of calling up its DamageMultiplier 100).