In conclusion, yes you're doing it wrong. I don't even remember specifically how the early-weapon aiming worked (and yes, it does change as you get higher powered weapons w/ different round velocities or subsonic rounds), but I do remember wiping out that first military checkpoint with headshots from the pistol. Weapon aiming/accuracy was an issue many people brought up, but all because they simply didn't understand the game's uncommon parabolic trajectory model and weapon sight function.
