this post got crazy without me i think i have infected all ur minds

 

pneumatic potato guns are a helluva lot better and safer than combustion ones. if your get the right pvc it can be rated to 300 psi. now with hair spray you get somthing like 20. for my engineering class we built a pneumatic one that shot a tennis ball 120 yards on 70 psi of pressure.

 

In my misspent youth, we used to make driveshaft cannons. You cut off the end of a drive shaft, make a little hole in the other end, fill it with welding gas's and shoot beer cans full of cement. Of course we didn't realize this was very dangerous. Now I've gotten a little wiser(not!), I have a cannon made by Southbend Replicas(web site), that shoots a 1" ball and takes 440 grains of black powder. Sound about like a half stick of dynamite!