here are some related links

a brilliant site, well worth registering.
http://www.spudtech.com

the best forum on the iternet
http://www.spudfiles.com

vortex strafer plans
http://www.burntlatke.com/bb.html

mechanical bbmg that im not sure about hhhmmm
http://www.swanstrom.net/petes/shoot/autobb.htm

the blow forward valve patent
http://airsoldier.com/~haveblue/tech/patents/US005908024.pdf

the pimpmans webpage
http://tonymann22.tripod.com

the most promising idea yet
http://www.classicairsoft.net/images/bv.htm