I have always been a little leery of using a sling shot
to send a line over a tree to raise an antenna.
My accuracy is not what I would hope and the occasional
ricochet is a little too exciting for me.
John Kalotai, N1OLO, wrote an excellent article for
the ARS Sojourner about using a throw bag.
Throw bags are used by professional arborists to get
a light line over a tree limb so that, they can then pull
up a heavier rope. The braided polyethylene rope
they use is a big improvement over mono-filament for me.
It pull through the tree very easily and does not tend
to wrap around a branch or itself.
You can get a throw bag and slick line from N1OLO.
Bartlett Arborist Supply
Sherrill - search for Item Number:"SET90"