On the range includes the firing line and the ready line which is usually 6-8' behind the firing line. This is the way military firing lines are run, but of course we don't have the issue of folks bringing weapons onto the range after we have started firing. They are all placed on the firing points at the same time and removed at the same time after being cleared by the RO's.
Additionally, shooters should only be allowed forward of the firing line after all weapons have been verified clear by the RO's and the line declared safe.
I don't want anyone behind me at the firing line handling a weapon while I'm down range in front of the firing line.