1fstdsl, When you say the Chrony was not "flat" did you mean that it wasn't level or that it wasn't open all the way? Not being fully opened would shorten the sensor spacings and I know that will skew the numbers. I've never given much thought about a chronograph being perfectly level, however. I just always line it up so that I,m shooting targets from the bench and speed testing at the same time. Our range seems like level ground but could be part of a degree out of level. Does perfect level make a difference?
I did not have the chrony fully opened. Which would probably explain why I would get frustrated sometimes when my velocities would flucuate by 100 fps.
