HurlingForums.com

We practiced with a 10 pound bowling ball quite a bit. It works great because of the consistent weight, size, and shape, but we found if we tuned our machine with the bowling ball, the tuning was completely different when we used a pumpkin so we basically started from scratch. It's still a cheap projectile for practice (you can get a crappy bowling ball for $20-$30 or cheaper at the Good Will). We never had a problem with damage but we always practiced in a grassy field. We also drilled holes all over to get the whistling effect which is really fun.

I paid $1.00 for a bowling ball at a yard sale once and I think it was $5.00 for one at a used-goods store but all the others I've had (20-30 of them) we obtained for free, by asking nicely. It also didn't hurt to briefly explain what they were going to be used for. I put out the word with friends and family and, after a while, balls started showing up.

Punkins have a completely different shape, texture and size when compare to BB's. At lower velocities the differences don't reveal themselves in performance but once the pouch loading and aerodynamics become bigger variables, yea...things change.

Mmmm... You've given me an idea. Must think around it a bit first...

This is a very interesting thread. Talking about the curved track, I have some ideas to get past that with very little stress. I would be interested in seeing the designs on this. I know the thread is 3 years old but it sounds real interesting. I will be working on an air cannon this winter. I may have to play around with this if the designs are still available and you can get them to me.