Unfortunately, CMBB doesn't model gun traverse. At least it doesn't appear to. I did a test case with 6 T-34 Fast Moving left to right down a paved road perpendicular to a 150 IG at 150 meters. When the IG spotted the tank, it started to travers left towards the tank. However, once it got there, the tank would pass from left to right and the IG would then start traversing to the right. The tanks was out of the field of view before the IG took a shot. The animation of the travers was of the entire carriage traversing, not the gun. The gun -did not- travers within the carriage at all. Note that if the IG has just held it original aim, it could have easily gotten off a shot as the tanks passed by but, instead, all 6 tanks passed by without a single shot being fired.
I then sent the tanks back across, this time on the very dry open ground. Here the T-34s were slow enough and the IG was able to take a shot at each of them. It hit slightly more then 50% of the time (the HC with its improved velocity was slightly more accurate.)
The simulation as is favors the T-34 in this situation due to the auto-track traversing.
Aaron