Thank you all for your comments, I honestly expected them to be much worse than they are.......
I have to say that the rail gun is part inspiration for this idea. Just cap off the ends. I also like the idea of using a pressure switch to eliminate timing issues. The other part of inspiration came from that flashlight you shake back and forth to charge it, perhaps it could be utilized to help charge the system. And as stated above (by Tsugury)I have never had an issue with the way current equipment works, however when in country where you have to carry everything you need, the weight becomes a serious issue. And as for the Punkin Chucker I have to say that I found that the pumpkin would (unfortunately) shred far before achieving orbit like velocities. Perhaps I should try a sabot system next time.....
Please keep the ideas coming,
Andrew