I carry a tight woven cloth about 10" square that I had sprayed with Camp Dry to make it water resistant. In rain or snow I drape it over my lock and use rubber band to hold it in place. (the T/C trigger guards are well suited for this because the hook where you place your middle finger when the rifle is shouldered is a perfect spot to place the rubber band once its over the lock).
I also check my powder every 1/2 hours or so.