case in point:
in my p38, tracers on, I jump someone from low left 6 (blind spot). Lets say rubber bullets make my first hits not damage anything.
From the victim's view: Hes flying level and all the sudden *pingpingping* and sees a few tracers fly from under his right wing flying away from him at his 1 oc. This pilot instantly knows im under him and to his left from just seeing the tracers and takes evasive action..
If there were no tracers, the victim would hear the pings, not see any tracers... and they will either jink a bit while they scan their views (giving me more time to shoot) or try a hard turn or split-s (which, them not knowing where i am, would very likely make them fly into my sights).
Not to mention the oh so many times im flying autolevel and see tracers zip by my cockpit and manage to evade before getting hit..all because the other guy couldnt shoot.. but if he had no tracers he couldve hosed me and i wouldnt know until i actually got hit.