I think a lot depends on the chronograph you're using. I have a Chrony Beta, and noticed one day that the numbers seemed a little high compared to previous sessions. The unit unfolds, and the hinge hadn't opened all the way, meaning the skyscreens were closer together than they should have been. Little things like that can skew your readings.
As far as the electronics go, I think most chronies are extremely accurate. It's actually a pretty simple machine........it sees a shadow, starts the timer, and shuts it off when it sees a second shadow. Then it calculates how fast the bullet was going. I think if they're used correctly, the results are probably within a few decimal points of perfect.

As far as the electronics go, I think most chronies are extremely accurate. It's actually a pretty simple machine........it sees a shadow, starts the timer, and shuts it off when it sees a second shadow. Then it calculates how fast the bullet was going. I think if they're used correctly, the results are probably within a few decimal points of perfect.