Surgical tubing puncher with pneumatic retraction:
http://www.chiefdelphi.com/forums/sh...highlight=rail
It is all about hitting a good peak ram velocity while it remains in contact with the ball. Having pneumatics pre-pressurized and surgical tubing prestretched with ram in retracted position is important. Rapid acceleration is what is needed, so a low mass ram with high initial force is best,
-Dick Ledford