"[The ProChrono}seems pretty reliable, and has done well with everything I've shot across it. I worry at times that the readings are not accurate, but I may just be worrying over nothing."
I have compared the results from two ProChronos directly to several other chronographs, by setting up the ProChrono at the same time so it will record the same shots. The first time I did this was with my Oehler 35P, during a range session that lasted around 4 hours, starting in early afternoon and ending when the sun was low in the sky. Light conditions obviously varied, but the PC held its own. The big difference is in distance between the light screens--the PC's are only a foot apart, and the Oehler's a minimum of two feet--which can be stretched considerably. The Oehler also has a third screen, providing a second check of the velocity reading--and prints a readout of every shot, on paper, if that's what you want, and is no doubt more accurate on each shot. But the average for each string from both chronographs was essentially the same.
I also checked that first PC against a second one, and they recorded the same velocities.
Did the same thing with my first Magnetospeed and the LabRadar, and given the difference between muzzle velocity (MS and LR) and the PC being at least 10 feet in front of the muzzle, the PC also recorded the same average velocity.
That said, the directions for the PC say to use the overhead filters on sunny days, but not use them on a cloudy days. I did check this out as well, and velocities will vary a little (not much) if you don't use the filters on sunny days.
