I don't want realistic ballistics unless you go all out. I want to see a really realistic game where one shot to center mass kills,
Which is, in itself, unrealistic. Incapacitate, very likely - but kill? No guarantees there. The surest way to kill with a firearm is to shoot someone in the head twice (single headshot has only about 50% mortality rate) or riddle the torso with bullets (damage to five or more major organs practically guarantees death). The mortality rate for a single shot to the center of mass is about 9%.
The reason for aiming at center of mass is because it's significantly easier to hit the target, not because it is necessarily more lethal - a missed shot has no stopping power.
and weapons have bullet drop and penetration and firing speed and recoil according to the actual ballistics of the guns. but this would only really work in either a stealthy delta ops or sniper type single player, and a massive team tactical in multiplayer. I would really love to see that actually.
It would also require longer engagement distances than are typically seen in games.
For example, an M16 has a muzzle velocity of roughly 950 m/s. For the bullet to drop a mere 1 cm, it has to travel about 40 m. At the under-100m engagement range typical of modern shooters, a bullet from an M16 will drop less than 6 cm. The relevant numbers for 7.62mm rifle like an AK-47 - muzzle velocity 715 m/s - are roughly 1 cm @ about 30 m and 10 cm @ 100 m.
(Of course, modern rifles in real life have adjustable sights that take bullet drop into account as long as they're set for the right range.)
You are talking to a fanatic gun nut, I'm aware what the numbers are. However, the noticed drop amount depends on type of sight, what range the sight is set for, length of barrel, humidity, altitude, barometric pressure, ect. And some of those, like altitude, length of barrel, and bullet weight can change the drop significantly even at just 100 yards. there are several problems with using accurate ballistics. I would suggest that any such attempt use the ballistics for a rifle set at 100 yards, and assume air temp/pres/humidity/ect. are all at constant values throughout the game, and use only the most common bullet weights.
Also, you are correct, it would require average engagement distances between 100 and 300 meters to make use of accurate ballistics, I just forgot to say so. Although, the 7.62X39(the AK) has significant drop at even 100 meters. Also, there are at around a dozen different rounds that fire a bullet with a 7.62 diameter, and all have very different ballistics. The 7.62X39 has, like you said, has about 4 inches of total drop at 100 yards, but the 7.62X72(AKA the .300 remington ultra mag) has virtually none.
(the problem is that they are only set for one range and the enemy is not often at that preset range)