OP- If I missed this I apologize. you mentioned your MO is to clean then sight in before season. Does this mean your rfile didn't have a lot of round's down the tube (after cleaning) when this happened? I don't know what this would reveal one way or the other, just curious. There is definitely something to all of this, and I wish I had it figured out. I believe it must happen only when a bunch of things come together at one time. We have shot a lot in when it's wet, and sometimes the point of impact has been spot on and does not seem to be affected. Other times it cause's us to hit high and gives heavy ejector marks.. We have noticed this more when there is extreme moisture in the air versus heavy rain? At least the times I can recall it happening. When this has happened, it has lasted for shot 1 only and then back to normal. The crazy thing is, the exact same rife and load etc, will shoot great when wet sometimes,and not other times. I need to look back at my notes to see how many rounds down bore after cleaning when this has happened to see if there is a pattern? Not saying there would be, but I would love to figure it out! Since we know the rifles can be affected by rain or moisture, we have been using balloons overy the brake/muzzle while hunting and have not had an issue , even in extreme rain. Also, we have shot with the balloon on, and it has not affected point of impact. My notes indicate wet/ rain but I wish I had documented if it was heavy moisture/ condensation or flat out rain. Very interested to follow this thread. Thanks for posting! Also, whatever it is, it must be a combination of the right kind of wet, the right amount of fouling etc, because it does not do it all the time!