When playing the quick missions, in the German fighters, i am getting smoked by the B17 gunners.....i do not attack from astern as a rule............sometimes ahead and sometimes at a 3 or 9 position. I am having problems getting hits and don't know how to judge the distance for gun convergence ranges...so i am always over or under with the guns...any help would be appreciated and any tips with the gun sight.Setting options for guns has not helped.