MADe,
I'm not sure I understand the phenom to which you are referring. Any chance you can try to describe it differently?
If it is a matter of closing velocity, then you are going to see shifts as the closure occurs. So, if you are using snap view and happen to be changing between say, FWD RIGHT to FWD as the target moves across one of the range display bands, you will see what appears to be a jump in range but is really just the game updating your range to Tgt.
If it is a static target (one that is basically co-speed and roughly the same direction), you won't see the range changing as quickly.
If I've missed the boat answering you, then feed me more info.
-Rodent57