HA! We built a potato gun in my applied physics class my junior year. We shot lots of stuff out of it and had a tone of fun. For these tests we shot a chunk of foam from a grouting sponge. We got on loan from the state university some fancy high speed camera gear and tested propellants to see which Gave fastest velocities. Turned out about anything with a "little squirt" of O2 from the torch in the "firing chamber" was pretty good.
That was a trick I tried when the teacher had a phone call.
Funny how I got As in the hard science classes but still wasnt all that bright.....
This is the same school that the shop teacher encouraged us to build our own treestands in welding class. Pretty cool place back then.
