Mark, I’m curious about your chronograph. I have two and am not totally satisfied with either of them. I have no interest in the barrel mounted units as I would like to be testing accuracy and velocity simultaneously.
You have two LabRadars? Or two chronographs?
I have been very happy with my LabRadar and my V3. What the LabRadar doesn't pickup the V3 will. Think about suppressed 22LR. They have sensitivity settings that need to be adjusted to have them read correctly. Like @Mark A Ouellette pointed out, you can purchase external triggers for them too. I use a magnetic switch for all my suppressed center fire rifles to make my life easy.