Haha - brilliant Si - I loved the stick test PMSL
The thread is getting very techie and theoretical, but don't let that put you off.
I think a quick run down is this... my initial tests looked pretty promising for the theory, your later tests threw up some questions. The 40fps downrange difference hitting the same height being a good one. I proved that in theory it was possible, but there's a lot of data coming in and none of us are sure of just how relevant / accurate that is.
Please don't take that the wrong way though - it's not a reflection on your tests, we're just kicking the crap out of a theory to see what comes out the other end.
Urm.. what else happened.. oh yeah, I got my physics badly wrong, but we're all gentlemen on here and the others courteously pointed out the error of my thinking. I've corrected that now and learned a bit in the process.
I think, most of us still think there's merit in the theory but it needs more data to make sense of it. So yeah, any downrange chrono'ing you feel like doing would be brilliant. If you shoot group's, is there any chance you could put something on the target as a reference for size - take a photo with a pound coin on the target for example. I can do some group size analysis then which might paint a clearer picture.
All good stuff though.. when we get to a clearer point, I might see if I can summarize everyone's conclusions so you don't have to wade through the whole thread for the answers.