Ironically I read this post this morning and hit the range this eve and took the lab radar with. Was shooting 22lr match ammo that was all sub sonic and could not get the trigger to pick up the sound to record velocities. I tried adjusting the trigger level and it didn't work. Then I switched the trigger source from trigger to Doppler. Bingo it worked! It just keeps the radar on. I put the suppressor on and was able to record velocities shooting a sub sonic suppressed 22lr bolt gun. I love the lab radar but the app interface sucks! Prochrono app is much more user friendly