Wasn't there a recent post about some one shooting LR cowhmpetition to firing line?).
Rain impeded visibility and they stopped shooting. Rain quit and the string was continued.
Comment made, again I'm going from memory here:( my search abilities are ziltch, was that the the rain made no noticeable difference in POI.
Visibility was the largest impact.
Personally a light drizzle is fun to shoot in. Makes windage easy to read plus the vapor trail is quite visible and that's fun to watch. Shots can be called well before they hit, pretty sweet.;)
I may be the slowest guy on the mountain . . . . but . . . . I'm on the mountain!