On May 16, 12:01*pm, Buck wrote:
The best was a converted shotgun. *I took a shotgun shell and took out
the shot, folded the plastic outer shell over the inner shell and
stuck a wood dowel into it. *On the far end of the dowel was a
screwdriver with an eye hook onto which I tied a string. *It cleared a
100 foot tree with room to spare, but I was afraid of the possibility
of damaging the gun itself so I only tried this once. *

Wow, a shotgun. I wouldn't be so much scared of damaging the gun, but
instead of the gun blowing up in my face!

The tennis ball cannon I use is very very similar to the CSV19 at
http://www.antennalaunchers.com/ and I am very very happy with it.
It's not so much a "point above a crotch in the tree and hope the ball
goes through" but "just shoot the ball and line over the tree".

Tim.