My guess is that it's something about the damage modelling and gunnery modelling. If AH really uses carefully selected realistic data, the only reason why it would bring unrealistical results would be they are not used in the correct(or, sufficient) manner. This may be due to technological issues or limits in current PC specs.
Changing the DM is probably gonna make heaps of people suffer and whine, and a still a lot of time and effort has to be put in it. However, as it is, it is probably the most lacking aspect of AH aside from graphics, and something HTC must go through in order to achieve a level closer to perfection
I have no idea how the damage is calculated, but so far, reading through the boards carefully sometime now, the only thing that would influence the hitting power of the fired round seems to be the initial kinetic state of the plane - ie. the power when you hit a plane with .50s at 200mph and 400mph will be different. I don't belive I've ever seen any other source of influence mentioned when people discussed the power of rounds - ie. Hispano discussions then and now.
This would lead to the problem of how sophisticated a gunnery model should be. IMO gunnery modelling and damage modelling is very closely related. In some other discussion where people compared the DM and GM between IL-2 and AH, there was a very solid statement by a beta-tester of IL-2 that IL-2 models the individual quality of shots fired - a explosive 20mm shell going off on the surface of an airframe is significantly weaker than a well-placed 20mm shell which digs into it and blows up inside.
This type of GM, which seems it is not perfected yet, sometimes brings out strange results(like a 30mm round hitting a plane and doing almost no damage to it), but is significant in that it brought up the difficulty in gunnery upto respectable levels which for so long people have sought in flight-sim games.
Unless you are close enough to verify that all your cannon rounds have hit with spectacular results, shooting a target at further distance than the "realistic shooting distances" noted in real-life anecdotes will result in blasphemous waste of ammo in that a) you can't assure the quality of the hits you've landed, and b) unless its a cannon round, it is very difficult to confirm your hits in the first place. In short, when there's a target further than 300 meters, you can't be sure if what you see is really what is happening. You seem to land hits, specks and shards fall off, see an shell explosion or two, but the enemy flies on.
However, this is exactly the opposite of what happens in AH. You can confirm hits easily, which promotes people shooting and spraying at long ranges, and also, the quality of hits are very lacking. If you land stray 20mm hits against an extending plane, the only thing that would affect the power of the hit attained is the relative speed and distance between you and the target. It would be weaker than firing up close and personal, but whether it grazes the surface, snips off a protruding antenna, blows up on the outer skin it will all be registered as if the round dug up into the structure and blew up inside. In short, the amount of damage assigned to a gun round is generic in every case, only specific according to speed or type of round.
Thus, when you fire three shells and only one of them is really "hit", the other two much lighter in damage, it will still calculate damage as "3x20mm rounds =XX points", and then subtract it from the hitpoint assigned to a plane structure. In real life the wing that sustained 1 heavy hit but two light hit might hold together, but in AH it would tear off. Couple this fact with the "all or nothing" DM and voila, you get the so-called "tough" birds dropping like flies - P-47s, IL-2 , and also people spraying and praying at 500~800 yard ranges and getting kills.
If the quality of the rounds hit are modelled, with better hit sprites according to type of ammunition, plus a more sophisticated damage modelling.. I have a feeling the IL-2 and the P-47 would really live up to its name as a "tough tough mutha".
