hey just wanted to add these links. It is a how to with nice pics:
http://popularairsoft.com/stories/piston-short-stroking
http://www.interq.or.jp/tokyo/akishi...y/spt/sptg.htm
I'm going to be short stroking (grinding only though) because my male piston will probably have a premature engagement problem haha . deepfire full metal rack + modify gearset. I have to check the AOE angle and see what I'm going to grind down first.