My bet is that you're aiming at about the right spot, firing at about the right time, but still not getting hits. Well, I must say then that M&B has the best ranged hit detection I've seen and I don't think that's the reason. There must be something else. If it's not the parallax problem causing weird aiming offset that you aren't familiar with, and if it isn't hit detection (because it's very unlikely), we're left with very few options. You've canceled out latency, but perhaps you're having frame lag. Are your graphics settings too high? You can enable an FPS counter in the options from the launcher, by going to Configure -> Video, and checking "Show framerate." If your framerate in battles averages less than 30, you should lower your graphics settings. Some people would say 60, but 30 is the minimum for playability.