Lee Nowell wrote in
:

I had assumed that the pipe had to be all the way in to exert the nut
tightening force in the olive.


By backing off slightly, the tightning force will be applied to both sides
of the olive. If the pipe is pushed all the way in then there is no
movement possible at the inner end so nearly all the final
deformation will be at the outer end of the olive. Think it through for
yourself and see if you agree.