I have an Xtrema2, and recently had it on a nasty, rainy, muddy goose/duck hunt. It did not stop raining the entire time I was out int the field. I sat in a small ditch, and occasionally the gun would fall in the ditch completly covered with mud and water. I never had it jam on me. Heck, I had never even cleaned the gun except for the first cleaning out of the box (probably 2000 round through it). I did give it a good quick cleaning after returning to the lodge (trigger not removed, but all else removed and wiped down and oiled). It still cycles anything I send thru it.
So, I personally have no reservations taking a semi-auto into the nastiest conditions.
So, I personally have no reservations taking a semi-auto into the nastiest conditions.