I am not certain, but I think what you are asking is that it seems like at a distance your tracers don't always accurately depict if you are hitting a player or not. There are a couple things going on that could cause this depending if you are the one being shot or doing the shooting.
First the actual projectiles you see are just visual representations, so while your projectile looks huge in the distance (like 3X the size of a player so that you can see it in the case of the changes I just made) it is not the actual size of the projectile being used to solve for a hit or not.
Another possibility is if you are the person being shot at, tracers really only help you figure out where the person is, as hit detection is done by the person doing the shooting. It is possible to see a tracer hit you and be okay, while the one that clearly misses you is a one hit kill. It all depends on the other client.