Thread: Which Chronograph?

I have a Prochrono that is over 20 years old, and a Magnetospeed V3 I bought secondhand. I fired 5 shots over both, for 3 of the shots there was only a 1fps difference between the two, IIRC the other shots were 10 and 50fps difference, which I am confident was due to the Prochrono turning a bit sideways due to muzzle blast from the previous shot (I had it much closer to muzzle than recommended).
Prochrono works great on overcast days, get some weird readings on sunny days (9147fps for my 308 last Thursday!). The Magnetospeed is much more consistent, but affects point of impact a lot, and possibly group sizes as well, so load development needs to be done separately from velocities.