Just wondering...

[bakfly]

I have shortened my pushrods with this method. I chuck the ball end in the drill press with the bottom end in a hole drilled in a piece of wood. Depending on how much you want to remove, use a hacksaw blade and cut the top end of the tube through to the hardened nipple. You won't scratch the nipple, it's too hard. Then put the push rod on a solid surface, fit a socket over the ball end and drive it down to the new seat. You can grind the hacksaw blade to any thickness you want to remove. Takes about an hour to do four rods.

I did exactly the same without any problems. You will not be able to take the nipple off the tube without destroying the tube.
Sonex 19-8464, AeroVee 2.1
Flown 140hrs