I'm not sure if this is a "puncher", but we were able to get an air cylinder to push the ball for a ~15 ft shot during our "proof-of-concept" stage. It took more work than you're expecting though:
1) You need a big cylinder. We used a 2" bore, 15" stroke
2) You can't deliver enough power through the FRC legal solenoid valves. Instead, treat the cylinder like a gas spring and pre-charge it.
3) Because you can't exhaust air through the solenoid valves fast enough either, you can't use the same cylinder to retract. Instead, you need a separate cylinder (or winch), and a release mechanism (basically all of the things you would need if you were working with surgical tube instead of a cylinder)
4) The cylinder should have a tank of at least equal volume attached directly to the port with hard pipe (preferably 1/4") *not* tubing. The extra volume of the tank will keep the pressure in the cylinder from dropping to nothing when it expands, but the flow restriction through the port puts an upper limit on power.
So in summary - doable, not much easier than a surgical tube slingshot, although it does let you vary force.
Check out this thread from a few years ago:
http://www.chiefdelphi.com/forums/sh...ad.php?t=79952