Re: Chrony Chronographs...
I agree that the absolute velocity that you measure will be more accurate if the skyscreens are spaced farther apart. Relative velocities between shots are different story. If I am reading your comments correctly, you seem to be assuming that there is going to be a 0.2" variation in the skyscreen spacing shot to shot, but that clearly isn't the case. Once you are set up, the screen spacing is fixed, the position of the chrongraph relative to the rifle is fixed, and as long as the lighting conditions aren't changing, the only real source of variablity is in the timing circuitry, and that's a pretty simple gizmo. One of the reasons the Oehler is the better instrument is that the timing is measured twice and compared for each shot, and even here the Oehler is going to give you an odd reading every now and then.