HT let me clarify what i was trying to say:
if like you said certian areas of the tanks were able to be penetrated by 50 calibre fire then fair enough let them penetrate.However like hortland has shown this was not common if indeed it EVER occoured. I have not seen any evidence that the 50 caliber could penetrate the armour but at the same time i have read that with the poorer types of armour used on some tanks on the eastern front often there were flakes or chips of armour that often injured crew members inside when machine guns hit them anyhow. Im aware that given perfect situations there are ways in which almost any weapon can kill tanks. Molotov coctails thrown onto engine grills, mortar rounds actually going through hatches, the 'stories' are endless but should all of these be modeled into a game when so much of the real world isnt? we dont have real weather, we dont have real forest cover or camoflage and we dont have the numbers deployed on a battleground. Its usually 1 guy in a tank spending 20 minutes rolling up huge hills when in real life they would use a road or train to transport them.There would be artillery support infantry etc etc. That poor guy in the GV has none of this protection.
SO what im saying is if a tank was pretty much safe against all but the luckiest of hits with a 50 calibre in real life then there is no need to introduce these rare occourances into the game in AH. Theres so much real stuff missing already that would favour ground vehicles its a wonder people use them at all.
Why do we use them? because we all crave the ability to blow things up in a huge armoured vehicle

and we try to ignore the fact we get killed all the time by machineguns. Im just fed up with it myself and as you can plainly see so are many others.
as to the 75mm model you speak of concerning areas hit/angle/distance then sure leave it AS IS if you feel its accurate.
same with the 50 cals if you say it could do what we see it doing in AH.But could you at least tell us just what 50 caliber is capable of penetrating? from what ive seen staga post its very unlikely in real life yet it is common in AH.I think losing the 50cal-30mm(he) damage to all but the very rear or top where armour is really thin would improve enjoyment and encourage use of the tank buster type planes.
Surely you'd like to see more use of il2s,hurricanes 40mm etc?
If we stick to the current model and invulnerability to 50 calibre or 20mm means a heavier tank than the panzer IV then ok but please hurry up and give us one before it drives me crazy.(Ive had too many long journeys with no action cut short, before i even see my target, by a single pass in a lightly armed p51).Mind you, then you wont see anyone using the panzer IV ever again as no one will want to be killed by marauding p51s or p47s etc

Also what I would like to know is the type of ammo used for each gun in AH.
50 cals are AP?
hispano MKII 20mm are AP?
hispano MKV 20mm are AP?
Mg151/20 are HE?
Mg131 13mm are HE?
MK 108 30mm are HE?
HO5 20mm are HE? AP?
NS 37mm are AP?
VYa 23mm are AP?
Shvak 20mm are HE?
UBS 12.7mm are ?
ive never quite worked it out myself. Couldnt we have some sort of guide to what we should expect to accomplish with these weapons?
maybe if we knew what to expect from these guns we would accept the model for panzers is acceptable? perhaps its time for tony williams to show us?

P.s. if like you said ap rounds tend to go through rather than destroy then why do ap rounds do so much damage to planes as well? shouldnt an AP round be good for armour but less usefull against thin skins of wings etc where they would pass through?
very confusing.